Ready Jet Go!



Ready Jet Go! is a very odd preschool (but not really) show from the mind of Craig Bartlett, who also brought us Hey Arnold! and Dinosaur Train. It airs on most PBS affiliates in the United States.

It involves a kid named Jet Propulsion and his family, who look like humans are are really aliens, who arrive on Earth to study it and write travel reports. Along the way, Jet befriends three neighborhood kids: Sean Rafferty (a space nerd), Sydney Skelley (a sci-fi fan and Greek mythology buff), and Mindy Melendez (a rather one-note little girl).

Also part of the cul-de-sac are Mitchell Peterson, an amateur detective who is hellbent on exposing Jet's alien identity, and Lillian, an air headed yet sweet girl who is a friend of Mindy.

Since this show airs on PBS, the show aims to teach the youngsters about science, in particular astronomy.

The show premiered on February 15, 2016 and was a huge hit for the public broadcaster. It was renewed for a second season, which premiered on April 2, 2018. Unfortunately, the show got cancelled in October 2019, with the final special airing on June 17, 2019.

This also goes for the four main DSA scientists: blonde (Dr. Bergs), brunette (Mr. Peterson and Dr. Skelley), and redhead (Dr. Rafferty). which allows them to hide in plain sight on Earth easily without anyone discovering their secret alien identity. Averted with Sunspot, some characters like Dr. Rafferty and Mitchell often question what kind of animal he is.
 * Abhorrent Admirer: Mindy is this to Mitchell, who she seems to have a crush but he doesn't like her back because she always sneaks up on him. However in later episodes he seems to reciprocate the feeling.
 * Aborted Arc: One potential story arc that got abandoned was a baby sibling arc for Mindy. In "So Many Moons", the root of the episode's conflict is that Mindy is worried about her parents having a new baby, but that plot line unfortunately was forgotten about.
 * Absentee Actor: Not all of the main characters appear in every episode. Jet and Sunspot are the only characters to appear in every episode.
 * Accidental Pervert: In "Satellite Selfie", Sunspot ends up being this because he accidentally took a picture of Mr. Peterson's butt.
 * The Ace:
 * Jet can be considered this. He has many talents, including singing and dancing, and he's the leader of his gang.
 * Sunspot is also good at everything.
 * Ace Pilot: Celery is an amazing saucer pilot. Since saucers are treated like cars, Carrot offhandedly mentions that Celery was voted Best Driver in the Bortron System for three years in a row.
 * Acquired Situational Narcissism: In "Not A Sound", Sean acts rather smug that he knows that there's no sound in space, yet Jet and Sydney don't.
 * Acting for Two: Multiple In-Universe examples:
 * In "Lone Star", Sydney plays a random citizen and Boxwood Territory's science teacher.
 * In "Holidays in Boxwood Terrace", Mindy plays the Head Elf and the Head Scientist in the pageant.
 * In "A Star is Born", Jet plays both hydrogen and helium in the kids' movie about the formation of a star.
 * Action Girl:
 * Commander Cressida is an in-universe comic book character who kicks serious butt.
 * Sydney, who idolizes Commander Cressida, can slip into this territory, especially when she co-pilots the saucer.
 * Action Mom: Celery. Besides being an Ace Pilot, she has super strength as revealed in "A Hammer and a Feather", and is generally the most action-y of the Propulsion family.
 * Acrofatic: Despite Sean's weight, he was able to do a perfect somersault over Jet's aunt, Eggplant in "Back to Bortron 7".
 * Adaptation Distillation: The books based on some of the show's episodes (like "Night of a Bazillion Stars" and "From Pluto With Love") remove some scenes and lines to make them shorter.
 * A Day In The Limelight:
 * "Commander Cressida Begins" mostly revolves around Sydney and Mindy. Jet and Sean do appear, but they have non-speaking cameos.
 * "Fact Or Fiction?" gives Lillian the most focus thus far.
 * Sunspot is the focus of "Sunspot's Sunspot".
 * Ad Break Double Take: A variant occurs in TV broadcasts of the two-parter, "Mindy Turns Five". (PBS doesn't have commercials, so live-action segments with Astronomer Amy Mainzer are used to fill the timeslot on this show) At the end of Part One, Mindy says "This is one small step for Mindy, and one giant leap for Stuffy Bear!" and she steps on the camera. At the beginning of Part Two, Mindy says it again and her stepping on the camera is accompanied with puff effects and the other kids cheering.
 * Added Alliterative Appeal: : In "Earth Camping", Carrot and Jet go through their packing list, which consists of pickle juice, a ping pong paddle, and a pocket protector. It turns out, that their "packing list" was the "P" section of the dictionary!
 * Adorably Precocious Child: All the kids count as this, especially Mitchell, who is about Mindy's age and can make an exact copy of Saturn V.
 * Adorkable:
 * The series star, Jet. With his Large Ham tendencies and naivety about "Earthie" culture, it's impossible not to love him.
 * Jet's dad also qualifies. He is a Bumbling Dad, but he is lovable nonetheless, especially since he cooks many odd Bortronian foods throughout the series.
 * Sean. He is an intelligent, cute, yet easily nervous Broken Bird with Youthful Freckles.
 * Even Mitchell can be this when he's not being a Jerkass, especially in the episode "Solar-System Bake Off!", where he acts socially awkward around Jet and his friends when he is trying to gather information about their entry, especially Mindy.
 * Dr. Rafferty can be this as times due to her awkwardness. For example, her "Standing in the Rain" ditty in "My Fair Jet".
 * In a way, Dr. Skelley is this trope due to still being an avid fan of the Commander Cressida franchise.
 * Adult Fear:
 * In "Back to Bortron 7", Eggplant informs Carrot and Celery that once they finish their presentation, they can never go back to Earth. Keep in mind that the Propulsions brought Sean and Sydney to Bortron 7 while their parents were out of town. Imagine your children being stranded on a planet thousands of lightyears away from Earth, taken by a crazy alien family, never to return ever. Luckily, Carrot and Celery's boss allows them to stay on Earth, so they get to return to Earth with their parents none the wiser.
 * In "My Fair Jet", the DSA weather balloon gets away in some nasty weather. Sean tries to grab it, but it ends up carrying it with him. You can tell by the expression on Dr. Rafferty's face that she is traumatized by her son flying away. Even Sydney was distraught. She pretty much begged Jet to forget his "Earthie" training just so he can save Sean.
 * Aerith and Bob: We have Mindy, Sean, Sydney, and then there's Jet. But to be fair, his parents thought Jet was an earth name.
 * Affectionate Gesture to the Head:
 * Dr. Rafferty gives one to Sean in "Face on the Fritz".
 * Dr. Bergs gives one to Mindy in "Solar System Bake Off".
 * Jet gives one to Mindy in "Moon Face".
 * Affectionate Nickname:
 * As of the episode "Constellation Prize", Sean refers to his mother as "Dr. Mom"
 * In season 2, Jet coins an adorable nickname for Sean -- Sean-zo.
 * Agent Mulder:
 * Mindy and Lillian, but especially Mindy. They believe that witches, ghosts, and the like are real as shown in "That's One Gigantic Pumpkin, Jet Propulsion!".
 * Taken Up to Eleven in "Fact Or Fiction?", where they both believe that clouds are made out of cotton candy, until they are proven wrong. Jet is also this.
 * Agent Scully:
 * Mitchell, on the other hand, doubts that Halloween is magical, until he is proven wrong at the end of "That's One Gigantic Pumpkin, Jet Propulsion!".
 * In "Fact Or Fiction?", Sean and Sydney don't believe that clouds are made of cotton candy. Obviously they're right, but Jet, Lillian, and Mindy don't believe them. Luckily, Sean and Sydney are proven right by the DSA scientists.
 * Agony of the Feet: In "Astronaut Ellen Ochoa", Bergs hurts his foot.
 * Alien Among Us: The whole premise of the show is that the Propulsions are aliens from the planet Bortron 7 who are living on Earth to study its customs, but must keep their alien identity a secret.
 * Alien Animals: Sunspot is kind of a mix of a rabbit, kangaroo, and raccoon.
 * Alien Arts Are Appreciated: Carrot grows to love Earthie cooking, even watching an Earthie cooking show in "What's a Satellite?".
 * Alien Lunch: Carrot tends to make many odd Bortronian dishes such as "deep-fried lollipops"
 * All CGI Cartoon: The show is animated in CGI.
 * Alliterative Name: Mindy Melendez and Sydney Skelley.
 * All Animals Are Dogs: Lampshaded within the show. Sunspot sometimes behaves like a dog, and people often confuse him for one.
 * All Deserts Have Cacti: In "Every Day Is Earth Day", Sean points out that deserts have cacti in them.
 * All Love Is Unrequited: Mindy's crush on Mitchell is unrequited. Though this trope is later averted in "Detective Mindy".
 * All of the Other Reindeer: In "Visit to Mom's Office", when Jet is telling Dr. Rafferty, that he is an alien, she says that she felt like an alien when she was a kid, which implies that she was teased as a kid.
 * All Work vs. All Play: Whenever the kids need to solve a problem, Sean wants to use the Scientific Method and work to get the problem solved, while Jet wants to play around and deliberately make mistakes in order to solve the problem.
 * Aliens Speaking English: The Bortronians can speak English perfectly.
 * The Aloner: In "Sean's Year in Space", Sean tries to live in the treehouse for a full year all by himself, but eventually comes down for dinner.
 * Almost Kiss: In the TV movie "Back to Bortron 7", during the Just Add Water number, Jet and Sydney are almost about to either hold hands or kiss, but Celery obscures the shot.
 * Amazingly Embarrassing Parent: In "Project Pluto", Dr. Rafferty unintentionally embarrasses Sean by mentioning that when he was four, he insisted on carrying a purple hippo plush everywhere.
 * Ambiguously Bi: Jet's sexuality has yet to be confirmed, but Jet always shows signs of being attracted to both Sean (a male) and Sydney (a female).
 * Ambiguous Disorder: Again, this is what Dr. Rafferty thinks when Jet reveals that he is an alien from Bortron 7, as "being from another planet/being an alien" is a common metaphorical description of what autism feels like. Sean could possibly have a high anxiety disorder due to being afraid of going to space and paranoid whenever someone touches his birthday telescope.
 * Ambiguous Situation:
 * In "You Can Call Me Albedo", it is unknown why Mitchell made Cody wear the black sweater in the first place.
 * The identity of Mindy's mother. Apparently, her mother as seen in "Jet Can't Sleep" is Dr. Rafferty and Dr. Bergs' boss from "My Fair Jet". However, when Mindy's mother is calling for her offscreen, she is voiced by Meg Roe. The boss was voiced by Ashleigh Ball. It is unknown if they are the same person or the animators got lazy and decided to use an already existing character model for Mindy's mom.
 * In "One Small Step", the kids land their saucer in Little Dipper Lake, where Mitchell is rowing a boat. When the kids are rescued by Mitchell, Jet explains that they built a super saucer and went to the moon. Later, Mitchell is invited to the kids' slumber party, where everyone, including Mitchell, sings about how hard it is to get back to Earth from space. It's really made unclear if Mitchell knows that the Propulsions are aliens or not.
 * American Gothic Couple: In the episode "The Mindysphere", Sunspot shows a picture on his tablet of Carrot and Celery posing as the American Gothic couple, with Carrot holding a rake instead of a pitchfork.
 * Amusing Alien: The Propulsions may as well be the prime example for this trope.
 * An Aesop: The show has Aesops in a few episodes, but they're unique in that they're woven subtly into the narrative of the episode instead of being shoved down your throat. Examples:
 * The moral of "Sounds Abound" is "Performing experiments is better when you're doing them with your friends".
 * An overall theme of the show is "Failure is a stepping stone to success".
 * "Kid-Kart Derby" has two: "Winning isn't everything" is the main one and "Don't cheat" is the minor one.
 * The show had a Be Yourself Aesop in the episode "My Fair Jet" that was surprisingly Played for Drama.
 * "Jet 2" - "It's not good to stay jealous".
 * "Space Junk" - "Knowing there's a problem should make you want to help solve it".
 * "Jet's Time Machine" had a very important one - "You can't change the past, you can only learn from it".
 * "Holidays in Boxwood Terrace" - "You should welcome other people into your friendship group".
 * "Racing on Sunshine" - "Don't be overconfident".
 * "Mindy's Bedtime" has Mindy want to keep the sun from going down so she can play more. Then, she learns about Sydney's pen pal Ahana, who lives in India. When it's day in India, it's night in Boxwood Terrace, and vice versa. When Celery takes the kids to a beach somewhere in the southern hemisphere, Mindy realizes that if she makes the day last a long time, Ahana won't get to wake up, resulting in a very subtle lesson on empathy.
 * "Ain't No Mars Mountain High Enough" has a moral about teamwork.
 * "Astronaut Ellen Ochoa" has the moral that the best solutions can come from the most unlikely places.
 * "Who Messed Up The Treehouse?" - "Problems aren't going away unless you help solve them. We should all take care of the place we live."
 * "Fact Or Fiction?" - "If something is too good to be true, it probably is. Do your own research to find out if something is true or not".
 * "Sean Has A Cold" teaches us that you can have a good time, even when things don't go your way.
 * Anachronism Stew: Lampshaded during the planetarium show, which includes Pluto as a planet, after it had been demoted, something Sydney points out.
 * And Knowing Is Half the Battle: Sometimes, the Amy Mainzer segments reiterate what was taught in the episode.
 * Animal Motif: Mindy seems to have a bear motif going on. She wears a bear hat, and she wears a different bear hat when she goes to sleep. She has a teddy bear named Stuffy Bear, who she dresses up as for Halloween. And her space helmet has bear ears on it.
 * Animation Bump: The animation in more recent episodes of the show is much better compared to older ones. The animation is much more high quality and puts detail into the character models.
 * Animesque: The characters' huge, shiny eyes and spiky hair on some of them could bring anime to mind. Also, the comic-book style transitions and montages resemble anime just a little bit.
 * Anti-Hero: Mitchell appears to be heading in this direction. Mitchell can be sarcastic, condescending, and harsh towards the group, but he has a few Pet the Dog moments that show that he can be nice. The Christmas Episode pretty much reveals that he's a lonely kid who just wants to have friends.
 * Are You Pondering What I'm Pondering?: Happens in a few episodes between Jet and one other person.
 * Arson, Murder, and Jaywalking:
 * In "Earth Camping", Mr. Peterson, Jet, Mitchell, and Carrot get lost in the middle of the woods on their camping trip. Carrot reveals that he has been marking their trail with Mitchell's jellybeans, but then a nearby squirrel comes and eats up the jellybeans that Carrot had laid.
 * Mitchell: Hey, that squirrel took all my jellybeans!
 * Jet: This is bad. He's eating our trail markers back to camp!
 * Carrot: Plus, his teeth are gonna be just awful if he doesn't brush.
 * In "Eye in the Sky", after it is discovered that it will indeed rain on the night of the Space Scouts' sleepout.
 * Mitchell: Bad news for Sean's sleepout, but good news for plants and flowers, and umbrella salespeople!
 * Art Shift:
 * In several parts of "Diggin' Earth", Sydney imagines Commander Cressida and her crew digging to the center of the Earth, in a 2D style.
 * Several times in the show, transitions and montages are drawn in a comic book art style, such as in "Sean Has a Cold".
 * Art Style Dissonance: The show has a somewhat simplistic but stylized art-style that appeals to young children, but the show itself is full of radar-dodging antics and quite a bit of Nightmare Fuel. Some mature themes are also implied such as PTSD, anxiety, racism, addiction, toxic parent-child relationships, and possibly more. Then again, Tropes Are Tools.
 * Ascended Extra:
 * Dr. Skelley, Sydney's mom. She was only ever mentioned by Sydney during some episodes of season 1, and appears in the very last episode of said season, but season 2 gives her a lot more screentime and focus.
 * Lillian only appeared in one episode of season 1, and another two as cameos. Season 2 bumps her from minor character status to recurring character status (most likely in part due to her being a popular character. Her appearances even rival those of Mitchell and Dr. Rafferty in terms of recurring characters.
 * Asian Airhead: It seems the writers are attempting to make Lillian this, but it's downplayed for the most part. In "The Grandest Canyon" she doesn't know what "perspective" means, and in "Mindy Turns Five", she outright tells Mindy what she got her for her birthday instead of keeping it a surprise like she said she would.
 * Attack of the 50-Foot Whatever:
 * In "The Plant From Bortron 7", Jet's Bortronian plant becomes enormous after it grows under the light of the Sun. It also becomes a monstrous Godzilla-like creature.
 * At the end of "Jet Shrinks the Kids", Mindy uses the shrink ray in reverse to become a giant, and startles Mitchell in the process.
 * Author Avatar: Jet is one to the series creator Craig Bartlett:
 * Craig Bartlett: “Arnold was how I felt being a kid and Buddy the T-Rex is really optimistic and doesn’t see how anything can’t work out and a friend to all. And Jet is even more so because Jet won’t shut up, you can’t get him down, he is always optimistic and he’s like the music man always bursting into song. When I was a kid, I thought wouldn’t it be fun if everything was a musical and people were always bursting into song. So I feel like he is the best iteration of my kind of personality that we’ve come up with yet.”
 * Awesome McCoolname: The Propulsions obviously have these names.
 * Badass Adorable: The kids, while definitely adorable, can be this occasionally. Especially in the one-hour special "Back to Bortron 7".
 * Badass Crew: Jet, Sean, Sydney, Mindy, Sunspot, and Face 9000 (with some assistance from Zerk and Jet 2) all prove to be this in "Back to Bortron 7", where they combine their efforts to save Carrot and Celery's presentation. Highlights include Zerk chauffeuring them to the headquarters in record time, Jet, Sean, and Sydney doing acrobatic stunts to get past Eggplant, Sunspot and Face 9000 saving the PowerCube, and Mindy and Jet 2 unintentionally causing an eclipse which distracts the townspeople from noticing that the Propulsion house is gone.
 * Bad Bad Acting: During the rehearsal of the pageant in "Holidays in Boxwood Terrace", Mindy performs her lines extremely woodenly.
 * Bait and Switch:
 * The episode "Mindy in Space" is about the kids pretending to take Mindy to space, complete with Mindy singing the take-off song.
 * In "Treasure Map", when Mitchell encounters the treasure chest, he is confused by its contents...and then declares that he loves it and does a dorky Happy Dance.
 * In "Astronaut Ellen Ochoa", the scientists hear footsteps approaching the door, and think it's Ellen. It turns out to just be the kids.
 * In "Mars Rock for Mom", when Sean shows his mom the rock he found, Dr. Rafferty comments that she knows where it came from. At first, Sean is worried that she knows that it came from Mars, but Dr. Rafferty says that she knows that it came from Sean.
 * Balloonacy: In "Every Day Is Earth Day", Sunspot is able to puff up like a balloon, and Jet flies away while holding on to him.
 * Banana Peel: Sunspot slips on a banana peel in "Mars Rock For Mom".
 * Batman Can Breathe in Space: Sean, Sydney, and Mindy can breathe in space, even without spacesuits with oxygen tanks.
 * Beach Bury: A photo on Sunspot's tablet from "Endless Summer" shows Jet being buried in the sand, and in the comic-book montage in "The Tide is High", Mindy is shown with a sand mermaid tail.
 * Beach Episode: "The Tide is High", where the kids try to figure out why the ocean looks different from when they last went there. Thankfully, there is no fanservice involved.
 * Bearer of Bad News:
 * In "Mindy's Meteorite Stand", Dr. Rafferty breaks the unfortunate news to Mindy that that her rock isn't really a meteorite, since it has quartz in it.
 * In "Project Pluto", Jet loses to Sean and Sydney in a game of "not it" and has to tell Mindy that Pluto is no longer a planet. However, he gets off easy because when he tries to tell her, she tells Jet that she already knew.
 * In "Back to Bortron 7", Eggplant tells Carrot and Celery that after they do their presentation, they're done with Earth. They respond appropriately.
 * Becoming the Mask: Implied. As shown in "Holidays in Boxwood Terrace", Mitchell fakes his jerk attitude to hide his loneliness and social insecurity. Even after he befriends the other kids in this episode, he still acts like a jerkass in some episodes of season 2, although he's mellowed out a lot more. Since he is shown acting rude towards the other kids in many episodes of season 1, it is implied that he's been hiding behind his jerk mask for so long, that it's become a part of his personality, and its something that he can't shake off, at least for the time being.
 * Benevolent Boss: As revealed in "Back to Bortron 7", Carrot and Celery's boss is one of the nicest aliens in the Bortron system. Also, Dr. Rafferty's boss in "My Fair Jet".
 * Berserk Button:
 * Sydney will get pissed if you make her miss one episode of Commander Cressida.
 * Sean will murder you if you get a fingerprint on his birthday telescope.
 * Mitchell hates it when people sneak up on him.
 * Be Yourself: Played for Drama in the episode "My Fair Jet". Jet wants to go to the DSA Open House with Sean and Sydney, but Sean and Sydney will only let him go if he behaves like a regular Earth kid. He can't say he's from Bortron 7, he can't use his "tool-armed backpack thingy" (which doubles as a jetpack), and he can't sing. However, at the Open House, the DSA weather balloon flies away in some bad weather, carrying Sean along with it. So, Sydney convinces Jet to be himself, so he can save Sean. He ends up rescuing Sean with his jetpack, and sings a song about how he is Bortronian. Pretty much, if Jet wasn't himself, Sean probably would've been killed.
 * Big Ball of Violence: In "Uncle Zucchini Babysits", Jet, Sean, Sydney, Mindy, Uncle Zucchini, and Moonbeam form one of these while trying to grab Sunspot so they can give him a bath.
 * Big Beautiful Woman: Eggplant, Jet's aunt.
 * Big Brother Bully: More like Little Brother Bully. In "A Kid's Guide to Mars", Face's younger brother, Face 9001, is mean to him, argues with him, and always try to show off, to the point of the original Face calling "MOOOOMMMMMMM!!!!!!!!" at least two times.
 * Big Damn Heroes:
 * In "Back to Bortron 7", just as Celery and Carrot are about to fail their presentation, Jet, Sydney, Zerk, Sean, and Sunspot save the day by putting on a musical number about how Earth is full of water, which convinces Carrot and Celery's boss to let them stay on Earth for another season. Actually, Zerk didn't even perform in the musical number, but that didn't stop him from bragging about how it was supposedly his idea.
 * In "One Small Step", Sydney and Jet 2 get their moment when they fix the super saucer together, allowing the gang to head back home. Mitchell also gets his moment when he saves the kids from drowning in the lake.
 * Big Eater:
 * Jet is this. It seems that every few episodes, he develops a new food interest, whether it be pie or sushi. He even listed eating as one of his favorite things in "Treehouse Observatory". Despite this, he is still very skinny.
 * Sean is this to a smaller extent. In "Sean's Year in Space", he tries to stay in the treehouse for a year but comes down when he smells pot roast. Also, it is revealed in "Whole Lotta Shakin'" that he stress-eats, and in "Project Pluto", he said that the Propulsions usually have snacks when the kids go to ask Carrot a question about Pluto, which earned him a funny look from Sydney.
 * Sunspot can also be this too. Sunspot eats all of Sean's peanut butter sandwiches in one episode, and scarfed down an entire pizza pie in another. He even ate an entire sub sandwich in "Mindy in Space".
 * The Big Guy: Jet is the tallest of all the children.
 * Big No: Zerk screams "NOOOOOOOOO!" at the end of "Whole Lotta Shakin'" after Jet throws his smartwatch away, which means Zerk can no longer bother Jet.
 * The Big Race:
 * In "Kid-Kart Derby", Jet races against Mitchell in the annual Boxwood Terrace Kids' Soapbox Derby.
 * The sequel episode "Racing on Sunshine" is essentially the same plot, but Sydney, Sean, and Mindy are involved, and in this episode, the kids have to design solar-powered karts.
 * The episode "Space Race" has Celery racing against her brother Zucchini.
 * The sequel episode "Asteroid Belt Space Race" has Celery and the kids racing against both Zucchini and Eggplant & Zerk.
 * Big Yes: In "Potatoes on Mars", when Jet suggests that they go to Mars, Sydney and Mindy shout "YES!"
 * Binocular Shot: This happens a lot, usually when Mitchell is spying on the gang.
 * Black Bead Eyes: Sunspot and Moonbeam both have these eyes.
 * Black Best Friend: Sydney.
 * Blah Blah Blah: In "Pet Sounds", Sydney says that all Cody hears is "Blah blah blah, food, blah blah blah."
 * Bland-Name Product: Jet mentions wanting to play Bortropoly when they get home in one episode.
 * Blonde, Brunette, Redhead:
 * Sean (Whose hair can sometimes appear blonde), Sydney, and Jet.
 * Bowdlerization: In "Just the Right Distance From the Sun", Sydney tells the story of Icarus to Sean, but mostly leaves out the part about his death.
 * Book Ends: The season 1 premiere, "Tour of the Solar System", starts off in Jet's backyard. The season 1 finale, "Commander Mom", ends in Jet's backyard.
 * Brain Freeze: Sunspot gets one in the beginning of "Mindy's Ice Rink".
 * Brainy Brunette:
 * Sean and his mom are both know a lot about science, and they both have brown hair. Although Dr. Rafferty's hair is a bit reddish.
 * Mitchell counts too.
 * And Mr. Peterson, who also happens to be a DSA scientist.
 * Bread, Eggs, Breaded Eggs: Happens in "Commander Cressida Begins".
 * Mindy: I guess, a planet. No, a moon. No, a planet with a moon?
 * Breaking the Fourth Wall:
 * In "Mindy's Weather Report", Mindy is watching TV and comes across a channel which is showing Dinosaur Train, one of Craig Bartlett's shows.
 * There's an extremely meta line in "Mindy and Carrot Bake": When Mindy and Carrot are stuck in space, they try to call Face 9000 for help, but they find out he's on vacation, which explains his overall absence from the show as of late season 1 and early season 2.
 * In "Mini-Golf at the DSA", Sean breaks the fourth wall when he says "Hey, that's my line!" in response to Mr. Peterson using his catchphrase.
 * In "Every Day Is Earth Day", after it is mentioned that Earth is the only planet with life, Jet looks at the audience and says "That we know of!" and then winks, since he's an alien from another planet.
 * Breather Episode: In some episodes, the show will take a break from teaching science to provide entertainment and character development in it's episodes: "My Fair Jet", "Jet's First Halloween", "Date Night", "Jet's Time Machine", "Mindy in Space", and "Holidays in Boxwood Terrace" all qualify for this trope, all of them having little to no actual curriculum (even though "Jet's Time Machine" provided an important Aesop and "Jet's First Halloween" tried to teach viewers about harvest moons).
 * Brick Joke:
 * In "What's Up With Saturn's Rings?", Mindy and Sunspot wish that Saturn's rings were made out of cookies. In "Solar System Bake Off!", the kids bake a Saturn cake for the titular bake-off. They make the rings out of cookies.
 * Mindy: I always wanted Saturn's rings to be made out of cookies!
 * In "Holidays in Boxwood Terrace", Mr. Peterson is annoyed at a random kid pitching him a pageant idea involving a surfing Santa Claus. In "Endless Summer", the kids go to Australia (during the Christmas season) and get to see a real surfing Santa.
 * Brief Accent Imitation:
 * In "Castaway Carrot", while Carrot is stranded on the moon, he decides to go in his "talk-with-an-accent" crater, and briefly talks with a British accent.
 * Carrot: 'Ello, guv'nor. Fancy a spot of tea or bangers and mash?
 * Carrot: 'Ello, guv'nor. Fancy a spot of tea or bangers and mash?
 * Broken Aesop: In "Solar System Bake Off", the kids aren't allowed to ask for help from grown-ups. Technically, they did ask for help by asking Jet's mom to drive them to Saturn to find out if it's cold outside, hot inside or the other way around.
 * Broken Bird: If you think about it, Sean really has it rough. Sean’s got a Disappeared Dad and a mother who’s almost always working. He’s also a huge perfectionist. He always needs everything to be the way he wants it to, and he gets very upset when he doesn’t get his way. He idolizes Neil Armstrong heavily, to the point of obsession, and wishes to be like him, but he can’t. Sean also fears cramped spaces, heights, and easily gets space-sick (and sick in general), which are things that are preventing him from becoming an astronaut. Despite wanting to be an astronaut, he heavily fears space, and is constantly forced by his friends to go. They never allow him to stay on Earth. He’s also somewhat of a Butt-Monkey within the group, and no one listens to him when he suggest using the Scientific Method to solve problems. He hides all of this pain with a Cheerful Child exterior. It makes you want to jump into the TV and give him a hug.
 * Broken Record: When Sean, out of nowhere, says "Help, help, help, help, help!" in "Sean's Robotic Arm".
 * Buffy-Speak:
 * The Propulsions talk like this sometimes, such as calling the humans "Earthies".
 * In "My Fair Jet", Sydney refers to Jet's robotic arm backpack as a "tool-armed backpack thingy".
 * Bumbling Dad: Carrot is this due to be very silly and often clueless compared to his wife. However, he provides helpful information to the kids and is a great baker.
 * The Bus Came Back:
 * In "Mindy Turns Five", Lillian finally comes back after disappearing for a while. She even had the same voice actor that she had in "The Grandest Canyon"!.
 * Sydney 2 and Dr. Rafferty's boss both reappear in "Astronaut Ellen Ochoa".
 * Butt Monkey: Due to this being a show for young children, this is very mild, but Sean seems to be this. He can't seem to ever catch a break. He's often the Only Sane Man in the group, always trying to think logically and use the Scientific Method, and yet no one listens to him. He's also absolutely terrified of going into space, but everyone always forces him to go against his will.
 * By the Lights of Their Eyes:
 * Briefly in "Jet Can't Sleep". There was a brief black out, and only the Propulsions' eyes were visible.
 * This also happens in "Astronaut Ellen Ochoa".
 * Call Back:
 * In "Holidays in Boxwood Terrace", Jet seems confused by Christmas at first, and Sean brings up how Halloween was confusing for him and his parents in the Halloween Episode.
 * "Endless Summer" includes a call-back to "Holidays in Boxwood Terrace", with Sunspot showing images from that episode on his tablet.
 * "That's One Gigantic Pumpkin, Jet Propulsion!" has a call-back to "Jet's First Halloween" when Mindy shows a picture of a witch (actually Jet) flying across the moon.
 * In "Mars Rock for Mom", a reference to the end of "Try and Try Again" is made, and is a crucial plot point. In that episode, the kids want Jet 2 to be their Mars rover, so they give him a new set of wheels and take him to Mars. However, Jet left Jet 2 there. During the time in which he was stranded there, he has adapted to the Mars environment and apparently formed a relationship with Boop.
 * Calling Your Bathroom Breaks: In "Back to Bortron 7", after Sydney asks him what he wants to do, Sean says he has to go to the bathroom. He never does actually go to the bathroom, though.
 * Came From the Sky: As shown in the theme song, Jet's house just fell to Earth.
 * The Cameo:
 * Dr. Rafferty, Dr. Bergs, and Dr. Skelley make cameos in "Every Day Is Earth Day".
 * For some reason, Mitchell makes a cameo in "Sunspot's Sunspot".
 * Camp Straight: Carrot. He does feminine activities such as cooking and ballet (as revealed in "Castaway Carrot"), wore a pink scarf in the aforementioned episode, and yet he is married to Celery.
 * Canine Companion: Cody, to Mitchell.
 * Cannot Keep a Secret:
 * Jet has a hard time keeping his alien identity a secret.
 * Even the Propulsions have a hard time keeping other secrets. In "Earthday Birthday", Carrot and Celery let slip that a surprise party is being planned to Jet, luckily they don't tell him that it is for him (to celebrate the anniversary of when he arrived on Earth).
 * Lillian can't keep secrets. She told Mindy what her surprise birthday present was in "Mindy Turns Five".
 * In "Moon Circus", Celery says that this is a shared trait between Jet and Carrot.
 * Cannot Tell a Joke: Face 9000 tries to take up comedy, but fails due to not being funny.
 * Cartoon Creature: Sunspot, as well as the other Bortronian pets such as Moonbeam. They look like dog-cat-bunny-kangaroo-raccoon hybrids. Uncle Zucchini even lampshades this in "A Visit from Uncle Zucchini".
 * Cartoon Juggling: In "Freebird", the shower variant occurs when Jet is juggling some meatballs.
 * Cash Cow Franchise: Commander Cressida, in-universe. It has a show, a comic book series, and tons of merchandise, including wristwatches, toys, backpacks, and Halloween costumes.
 * Cassandra Truth: Expertly played with in "Back to Bortron 7". In order to keep the Propulsions' alien identity a secret, Jet 2 has to project a hologram of their house so that no one would notice that they were gone. However, Jet 2 later has trouble keeping the hologram stable, which leads to it glitching. Mitchell even stays up all night to prove to his parents that the Propulsions are aliens from another world. However, when he takes his father outside, the hologram is perfectly fine, which leads to Mr. Peterson scolding Mitchell for waking him up at 2:00 AM. When the Propulsions are just about to land back on Earth, the hologram disappears completely, and then Mitchell tries to expose Jet's secret to the entire population of Boxwood Terrace, however Jet 2 causes an eclipse which distracts the townspeople from seeing the Propulsion house land back on Earth. Mr. Peterson scolds Mitchell again, telling him that he has quite an imagination, but Mitchell claims that he has no imagination.
 * Cast of Snowflakes: Somewhat. All of the characters have unique designs, especially the adults.
 * Casual Interstellar Travel: The flying saucer can go to space in a short amount of time. This is because they have interstellar overdrive.
 * Catch Phrase:
 * "Excelsior!" (onward and upward in Latin) - Jet
 * Also, "SUNSPOT, CAR TRIP!" and "What an amazing/funny/great Earth word!"
 * "Let's think scientifically" - Sean
 * "A kid's place is exploring space!" - Sydney
 * "POPPYCOCK!" - Western!Sean in "Lone Star".
 * "Hi, I'm Astronomer Amy Mainzer." - Amy Mainzer
 * "So the next time you do X..." - Amy Mainzer
 * "Booyah, science!", which has been said by multiple characters, but most often said by Sean.
 * “Hello. Yes. Play. Haha.” - Jet 2.
 * Celeb Crush: Dr. Bergs seems to have one on Ellen Ochoa. He has a coffee mug with her face on it, and when she shakes his hand, he looks at his hand and smiles with absolute glee, almost like he's thinking "I'll never wash this hand again!". Dr. Rafferty can be seen giving him a funny look after that happens.
 * Central Theme:
 * No matter what happens, keep a positive attitude and persevere through obstacles, no matter how impossible they may seem.
 * Another overarching theme of the show is that Earth is a beautiful planet that is worth protecting.
 * Cerebus Rollercoaster: Beginning with the episode "What Goes Up..." the show constantly switches between having cute, light-hearted episodes and having dramatic, emotional, and sometimes even dark episodes.
 * Character Check: Even though Mitchell has been taking a level in kindness in Season 2, in "Our Sun Is A Star!", he's just as mean as he was in Season 1. However, this episode takes place in January, and Mr. Peterson is shown taking down Christmas decorations, so it's possible that this episode could have taken place after "Holidays in Boxwood Terrace", where Mitchell becomes part of the group. That episode was one of the very last Season 1 episodes, and Mitchell didn't start becoming nicer until "Try and Try Again", a Season 2 episode.
 * Character Development:
 * As time goes on, Sean becomes less and less scared of going to space. He even calls himself "Mr. Adventure".
 * Zerk was initially stuck up and rude towards Jet and his friends. Come "Back to Bortron 7", he is much nicer to them, but still keeps a bit of his It's All About Me attitude. In "Zerk Visits Earth", his vain attitude disappears completely, and he is polite and respectful towards his cousin and the Earthies.
 * Mitchell was a bit naive before, as he actually believed Jet when he told him (in his alien costume) that he was from Bortron 7 in the Halloween Episode. Come season 2, however, Mindy explicitly tells him that she went to the moon, and even holds up a moon rock, but Mitchell doesn't believe her. Besides that, he is shown to have taken a level in kindness, especially in the second half of season 2.
 * Character Tics: Jet often walks with his elbows out, as if he's marching.
 * Character Title: The title has Jet's name in it, and it is named after the Jet Propulsion Lab. It also helps that the show used to be titled Jet Propulsion.
 * Cheerful Child: All of the children count as this, but special mention goes to the protagonist, who sees the good in everything, is a Friend to All Living Things, and is perpetually enthusiastic.
 * Cheesy Moon: In "Mindy Turns Five", it's implied that Mindy told her teddy bear that the moon is made out of green cheese.
 * Chekhov's Gun: The big rock Mindy sits on in "Mindy's Meteorite Stand".
 * Child Prodigy: The kids all seem to be this. They are all extremely smart for their age.
 * Chirping Crickets: In "Ice Moon Enceladus", the kids make their own sno-cone stand so they can raise money to send astronauts to Mars. Sean insists that since it's so hot out, they should be able to sell a ton of them, but then crickets start chirping since no one is there.
 * Christmas Episode: The show now has its own Christmas half-hour special entitled "Holidays in Boxwood Terrace", that focuses on the gang putting on a Christmas pageant and desperately trying to seek and define the Spirit of Christmas.
 * Chroma Key: This is used in the Amy Mainzer segment in "Back to Bortron 7".
 * Chuck Cunningham Syndrome: Face 9000's brother, Face 9001, only appeared in the episode "A Kid's Guide to Mars" and never came back.
 * Cloudcuckoolander:
 * The Propulsion family seems to be this at times, with their wacky antics.
 * Even though Sunspot is usually weird, he acts weirder than usual in "Sunspot's Sunspot".
 * Cloudcuckoolander's Minder: Sydney and Sean are both in charge of making sure Jet's crazy ideas don't get out of hand.
 * Color-Coded Characters:
 * Red - Mitchell.
 * Orange - Mindy, Sunspot, Face 9001, and Dr. Bergs.
 * Yellow - Mr. Peterson and Uncle Zucchini.
 * Green - Eggplant, Zerk, and Sean.
 * Blue - Jet, Carrot, Celery, Moonbeam, Face 9000, Dr. Rafferty, and Dr. Skelley.
 * Grey - Sydney.
 * Pink - Lillian.
 * Color-Coded for Your Convenience: Celery's saucer is blue, Zucchini's saucer is green, and Eggplant's saucer is pink.
 * Combat Commentator: In "Space Race", while Celery and Zucchini are racing, Sydney briefly provides sports-like commentary.
 * Comically Missing the Point:
 * As noted above, in "Earth Camping", a squirrel eats all of the jellybeans that Carrot had been marking their trail with. Mitchell and Jet are concerned that they are lost, but Carrot is only concerned about the squirrel's dental hygiene.
 * At the beginning of "The Mindysphere", Sean tells Jet and Sydney about how his mom taught him about the heliosphere while eating breakfast. Jet is only interested in what Sean had for breakfast.?
 * In "Sean's Neptune Tune", Sean keeps running away from Jet and Sydney because he doesn't want to go to Neptune. While Sydney realizes that Sean is upset, Jet thinks that Sean is playing hide-and-seek.
 * In "Earthday Birthday", Sean, Sydney, and Mindy make up a lie that they're planning a surprise party for "Brett", so Jet won't find out that the party is actually for him. Jet thinks that Brett is real and starts to look for Brett. Later, when Jet comes to the surprise party, the other kids explain that Brett isn't real, but Jet still thinks that he is and wonders where he's at.
 * Comic Trio: Jet, Sean, and Sydney. Jet comes up with crazy ideas, Sydney blindly follows, and Sean is the Only Sane Man.
 * Companion Cube: Sean, Sydney, Mindy, and Mitchell all have one. Sean has his Neil Armstrong action figure, Sydney has her Commander Cressida action figure, Mindy has her teddy bear, Stuffy Bear, and "Sean's Robotic Arm" reveals that Mitchell has one as well - his Sherlock Holmes action figure.
 * Constantly Curious: Mindy. 8 times out of 10, her questions are what prompt the kids to go into space. In fact, all the main kids could qualify for this trope, giving the likes of Curious George and Sid the Science Kid a run for their money.
 * Continuity Cavalcade: In "My Fair Jet", one of the tasks that Jet has to do in order to be a regular Earth kid is to sort a bunch of pictures that Sunspot took in previous episodes, such as the butt picture from "Satellite Selfie", and the Great Red Spot Club group picture from "Sunspot and the Great Red Spot".
 * Continuity Nod:
 * In "Mindy Pet-Sits", Mindy comes across the meteorite that she found in "Mindy's Meteorite Stand".
 * In several episodes, the kids point out how they have already been to certain planets.
 * Jet builds a robot in the episode "Jet 2". In later episodes, the robot can be seen around the children.
 * Some in "Mindy Turns Five::
 * Similar to how Mindy was jumping on the bounce house in "Mindy's Moon Bounce House", she is seen jumping on it again, and is singing a song that is sung to the tune of "My Name is Mindy".
 * Before the gang gets back to Earth, they look at and describe Earth like they looked at and described it in the episode "Tiny Blue Dot".
 * The gang goes to Pluto a second time, and they sing "Dear Little Frozen Pluto" again.
 * The squirrel that ate Mitchell's jellybeans in "Earth Camping" makes several more appearances throughout the show, in "The Mindysphere", "Space Race", "Jet Shrinks the Kids", and in "Mindy's Bedtime", he is finally given a name: Floyd.
 * In "Galileo, Galileo!", Mindy unintentionally makes Sean nervous to do his report on Galileo, and while doing so, Sean imagines himself on the exact same stage that the kids did their Christmas pageant in "Holidays in Boxwood Terrace", which is where Sean got nervous to perform his song in front of everyone.
 * In "Total Eclipse Block Party", Sean and Sydney initially won't let Jet perform on the DSA stage for fear that he will sing and use his Bortronian robot arms, which is a reference to the events of "My Fair Jet".
 * "Racing on Sunshine" takes place one year after "Kid-Kart Derby".
 * "That's One Gigantic Pumpkin, Jet Propulsion!" takes place one year after "Jet's First Halloween".
 * In the same episode, Jet uses the Bortronian sun lamp from "The Plant from Bortron 7" to grow a pumpkin.
 * In "Astronaut Ellen Ochoa", Mindy's love for Pluto gets mentioned again.
 * In the same episode, Sean setting up a lemonade stand to raise money for a rocket to Mars is similar to the plot of "Ice Moon Enceladus".
 * In "Potatoes on Mars", Sean says he sings in the shower, which was previously mentioned in the Christmas Episode.
 * In "Bortron Leprechaun", Jet's birthday badges from "Earthday Birthday" get brought up again.
 * In "Magnet, PI", Mitchell's scooter from "Try and Try Again" makes another appearance.
 * Convenient Eclipse: Played straight in "Back to Bortron 7". When Mitchell is about to expose Jet's secret to the entire town, Jet 2 causes an eclipse which distracts the townspeople from seeing the Propulsion house land back on Earth.
 * Cool Big Bro: Mindy sees Jet as one, and he does act as one to her due to his caring, optimistic personality. He even gives her a piggyback ride in "Project Pluto".
 * Cool Big Sis: Sydney serves this role to the other group members. She's easily the most level-headed, wise member of the group, and she's also a creative (if a bit over-ambitious) go-getter with a kind personality.
 * Cool Pet: Sunspot. He is very intelligent and can pull objects out of Hammer Space.
 * Cool Shades:
 * Sunspot wears some sometimes, such as when he's playing the instruments to Jet's songs.
 * In "Sunspot's Sunspot", Dr. Rafferty gives the kids some colored sunglasses to wear so they can see what it's like to live on a planet with a different colored sun. Jet has a little too much fun with it, much to Mitchell's annoyance.
 * Cool Uncle: Uncle Zucchini. He's a fun and friendly guy who is an intergalactic garbage-man.
 * Cowboy Episode: "Lone Star", where Sydney tells the rest of the gang the story of a pioneer named Lone Star who built the town's first observatory on a hill. It is also a Western-flavored Musical Episode. "Lone Star 2 - Rocket Kids!" is also this.
 * Credits Gag: In episodes like "Backyard Moon Base", the Commander Cressida theme song plays in the credits.
 * Crazy Enough to Work:
 * Many of Jet's ideas are this.
 * Sean's idea to combine various items together to make a robotic arm is explicitly stated by Sydney to be this in "Sean's Robotic Arm".
 * Crazy Prepared: A Running Gag in "One Small Step" involves Sunspot conveniently packing a lot of items the kids need and pulling them out whenever they needed. He packed food, Mindy's teddy bear, a moon rover, a parachute, and more.
 * Creator Provincialism: The series takes place in Washington state, where the creator, Craig Bartlett, grew up.
 * Cuddle Bug:
 * At least implied with Jet. He always puts his arm around Sean or Sydney (but mostly Sean), sometimes putting his hand on the former's chest or back. He also seems to enjoy group hugs, as evidenced in "Back to Bortron 7" and "Racing on Sunshine".
 * Mindy is also this. She always hugs Sunspot or one of the older kids (mainly Jet). In "Sean's Robotic Arm", she hugs Mitchell.
 * Curtains Match the Window: Mindy has brown hair and brown eyes.
 * Cutaway Gag: In "Every Day Is Earth Day", when Jet mentions how he and his family always mix up certain words, it cuts to Carrot and Celery hammering toasts on the wall, instead of posters.
 * Cute Machines: Beep and Boop, the twin rover sisters. Beep lives at the DSA and Boop lives on Mars.
 * The Cutie: Jet proves to be this trope entirely with his adorkable tendencies. Mindy and Mitchell also qualify for this trope.
 * Dark Horse Victory: In "Asteroid Belt Space Race", Eggplant and Zerk end up winning the race because of their anti-gravity fluxinators.
 * Deadpan Snarker: Mitchell, Mindy, and to a lesser extent, Sean.
 * Defrosting Ice King: Mitchell in "Detective Mindy", where he becomes kinder than he usually is.
 * Determinator: All the Propulsions are this, as they never give up. In fact, there's no word for failure on Bortron 7. Jet even has his own song about not giving up.
 * Deus Ex Machina:
 * Sunspot often functions as this, figuring out what is going on and what needs to be done and then conveying that information to one or more of the children.
 * Some of these occur in the secret alien identity arc. In "Visit to Mom's Office", Jet openly tells Dr. Rafferty that he is an alien from Bortron 7, but luckily, Dr. Rafferty thinks that Jet is pretending to be an alien due to "feeling" like one. And the residents of Boxwood Terrace don't notice the Propulsion vehicle transforming into a flying saucer.
 * As mentioned above, Jet 2 causes an eclipse in the TV movie "Back to Bortron 7", which distracts the townspeople.
 * Demoted to Extra: Face 9000. Back in the day, he appeared in practically every episode alongside the rest of the Core Eight: Jet, Sunspot, Sean, Sydney, Mindy, Carrot and Celery. Ever since "Sunday Drive", he has been making less and less appearances. Nowadays, the kids usually get answers to their science questions from Celery, the DSA scientists, or by figuring it out themselves.
 * Depending on the Artist: For whatever reason, the characters' looks can change from episode to episode.
 * Mindy might have slightly darker skin but reddish-brown hair, or slightly lighter skin but blackish-brown hair. Also, Mindy might be way shorter or the same height as Mitchell.
 * Sean may either have light brown, reddish-brown, or flat out blonde hair. His eye color also varies. It might be green, blue, or grey.
 * Sydney sometimes has a different color hair-tie than her usual yellow, like green or red. She might even wear grey leggings at night as shown in the end of "Back to Bortron 7" and "Jet's Time Machine".
 * Jet's hair color also varies. It might be reddish-orange, red with orange tips, dark red, or even pink! (Jet seems to have pink hair in the beginning of "Lone Star".)
 * Depending on the Writer: In some episodes, Mitchell can be a quiet yet obedient spy and in other episodes, he can be cold and anti-social.
 * Dick Dastardly Stops to Cheat: In "Asteroid Belt Space Race", Eggplant stops to turn on the anti-gravity fluxinators in her saucer. Upon using them, the other saucers lose gravity, causing Eggplant and Zerk to win the race.
 * Didn't Think This Through: In "Kid-Kart Derby", Mitchell finds the plans for an ion drive, but it does not work because Mitchell didn't read farther down in the plans.
 * Disappeared Dad: Sean says he has a dad in "Night of a Bazillion Stars", but he is never seen, though Sean's mom is always shown.
 * Disco Dan: Jet is shown to be fond of notably dated music, specifically '50s rock and roll and Broadway.
 * Disproportionate Restitution: In "Ice Moon Enceladus", the kids set up a sno-cone stand in order to raise money to send astronauts to Mars. Now, an important characteristic of Sean's is that he wants to grow up to be the leader of the first human mission to Mars. Mr. Peterson comes by the kids' sno-cone stand, and Mindy informs him that buying a sno-cone will help send Sean to Mars. Mr. Peterson recognizes Sean as the kid who keeps kicking his soccer ball into his yard, and then Mr. Peterson proceeds to purchase several. In short, Mr. Peterson wants to send Sean to Mars just for kicking his soccer ball into his yard.
 * Distant Reaction Shot: In "Sydney 2", Sydney builds the eponymous robot, who is a female version of Jet 2 and is designed specifically to be friends with him.
 * Distressed Dude:
 * In "My Fair Jet", the DSA weather balloon flies off in some nasty weather, and carries Sean along with it. But luckily, Jet saves him with his jetpack.
 * In "Castaway Carrot", Carrot gets stranded on the moon but gets rescued by his family.
 * The Ditherer: "Commander Cressida Begins" explores Mindy's indecisiveness on where to go next in space. Luckily, she learns that just like Commander Cressida, she can explore space one adventure at a time.
 * The Ditz:
 * Jet and his dad both qualify, but especially Jet since his friends keep telling him to not tell anyone he's from Bortron 7, and yet he still does. Luckily, when he told Sean's mom, she thought that he feels like an alien, like she did when she was a kid.
 * Lillian, who believes in ghosts and witches, can't keep secrets and doesn't know what perspective is. She also unironically believed that clouds were made of cotton candy in "Fact Or Fiction?".
 * Uncle Zucchini. In his debut episode, he believed that Saturn's moon Titan was Earth. In "Uncle Zucchini Babysits", he was somehow unaware of the three states of matter.
 * Ditzy Genius: Again, Jet is this. Jet can name every one of Jupiter's moons, but can't try to keep his alien identity a secret.
 * Do-Anything Robot: Sydney's mom programs Jet's robot clone, Jet 2, to a robot that can do practically anything in the season 1 finale. He is renamed to Jet 3.
 * Does This Remind You of Anything?: In "Who Messed Up The Treehouse?", the kids all make a huge mess in the treehouse. None of them want to take responsibility for the mess. They try to find different places to play, but they don't work out. They eventually realize that this problem isn't going away unless they do something about it, and that they only have one treehouse, so they have to learn to share the responsibility and clean it up. This is a metaphor for the trash problem on Planet Earth, and how Earth is the only place we can live, so we have to take care of it.
 * Do I Really Sound Like That?: Sean says this in "Back to Bortron 7" after a bunch of TV screens show him saying "Booyah! Science!"
 * Does Not Like Spam: In "Mindy's Weather Report", Jet reveals that he hates ice cream. This hatred is also shown in "Asteroid Patrol" and "Detective Mindy".
 * Don't Sneak Up On Me Like That:
 * Mitchell hates it when people sneak up on him. In the episode "What Goes Up...", Mindy sneaks up on Mitchell as he is spying on Jet. He gets very startled. No violence is involved, since this show is for young children.
 * In "Holidays in Boxwood Terrace", Mitchell berates Jet for unintentionally sneaking up on him.
 * Don't Try This At Home: In "Our Sun Is A Star!", when Dr. Rafferty conducts her experiment with the campfire and poker, she warns the kids to not try the experiment at home.
 * Double Meaning Title: "A Star is Born" both refers to the educational theme of the episode (how stars are born) and the plot of the episode (the kids making a movie).
 * The Drag Along: Whenever the gang has to go on a space mission, Sean always wants to stay on Earth. He is always forced to go regardless.
 * Drama Queen:
 * Jet is this in the episode "Jet's Time Machine". He builds a time machine, and he wants to go back in time because the previous weekend, he ate a delicious pie and forgot to ask for seconds. Then he makes a big deal over it.
 * In "The Tide is High", Sunspot makes friends with a crab. When he discovers that the crab is gone, he gets way too upset and faints on Dr. Skelley's lap.
 * Dr. Bergs is this in "Astronaut Ellen Ochoa" when his coffee mug with Ellen Ochoa's face on it breaks.
 * Drink Order: In "Astronaut Ellen Ochoa", Ellen Ochoa drinks some lemonade from the kids' lemonade stand. This gives us some insight into her character by telling us that even though she's a major scientist, she's really just a normal person and is also One of the Kids.
 * Dynamic Entry: Zucchini slides right on into Boxwood Terrace, in "Uncle Zucchini Babysits", complete with Moonbeam playing guitar.
 * Early Installment Weirdness: The earlier episodes of the show are very strange to watch in comparison to the later ones. There's the wonky CGI, voices being higher or lower pitched than normal, the show having a very small cast of only eight characters, episodes following the same format, and weird one-off jokes such as Mindy taking jiu-jitsu lessons and Bortronians having super hearing. However, they're still entertaining to watch and the show eventually starts to improve in quality.
 * Eat the Camera: During the takeoff song in "Back to Bortron 7", the camera zooms in on Sean's mouth.
 * Eccentric Townsfolk: While the Propulsion family are obviously a Quirky Household, the people living in Boxwood Terrace are all eccentric in their own ways. We've got:
 * A perfectionist Child Prodigy who idolizes Neil Armstrong and fears going to space.
 * science-fiction geek who is obsessed with Commander Cressida and writes fanfiction.
 * A geeky little kid who tries to be a detective.
 * A girly Asian Airhead.
 * A DSA scientist whose past is very mysterious, but she says that she felt like an alien when she was younger, hinting at this.
 * Another DSA scientist with an obsession for coffee.
 * A robotics engineer who still loves Commander Cressida.
 * Another scientist who always speaks very bombastically, is the judge/referee of every single contest in the neighborhood and is somewhat of an Extreme Doormat. He also treats mini-golf as Serious Business.
 * And then we have Mindy, possibly the token normal, since she is so incredibly generic that she has no quirks to speak of.
 * Edible Theme Naming: The Propulsion family, with the exceptions of Jet and Zerk, are named after vegetables. Examples: Carrot, Celery, Eggplant, Zucchini, and Spinach. Jet even calls himself Cucumber in the Halloween Episode.
 * Edutainment Show: This show teaches kids about Earth science (gravity, force) as well as space science (planets, the Sun) but also gives good lessons.
 * Ensemble Cast: While Jet is definitely the main character, Jet, Sean, Sydney, Mindy, Sunspot, Carrot, Celery, and Face 9000 (or "the Core Eight") all get episodes focused on them.
 * Episode Title Card: Appears during the first few seconds of every episode, and also credits the writer of the episode.
 * "Everybody Laughs" Ending: Happens in a few episodes.
 * The Everyman: Sydney and Mr. Peterson.
 * Everyone Is a Suspect: Played with in "Mindy's Mystery". The kids interview everyone they know and interrogate them about the mystery smell.
 * Everything's Better with Rainbows: The entire premise of "Bortron Leprechaun". Jet sees a rainbow for the first time and thinks it's the most beautiful and magical thing he's ever seen.
 * Everything's Better with Sparkles: Mindy sure thinks so as shown in "Every Day Is Earth Day", but Sean isn't sure how that will improve her poster.
 * Everytown, America: Boxwood Terrace, a fictional town located in Washington state. It is quite the Quirky Town.
 * Excited Kids' Show Host: Amy Mainzer, the host of the show's interstitial segments, is a Type 3. She can be quite energetic at times, but normally talks in a calm manner and never talks down to kids. Her segments also appeal to adults.
 * Excited Show Title!: Ready Jet Go!
 * Exploding Closet: In "Space Junk", Jet tries to clean the garage by stuffing all of his boxes in the closet. Then the closet explodes, letting all the boxes out, and the garage is messy again.
 * Expository Theme Tune: The rather catchy theme song of this show explains the plot of this show in one minute.
 * Expy:
 * Celery is an expy of Miss Frizzle from The Magic School Bus. They are both eccentric ladies with red hair, and they drive vehicles that take children on wacky science adventures.
 * Sean is also an expy of Arnold from that same show, because they are both butt monkeys and lovable cowards, and are always hesitant to go on trips.
 * Eyedscreen: Used in "Racing on Sunshine" when the camera does a closeup on Mitchell's eyes during the race.
 * Face Palm: Happens quite often. For example, Mindy face palms in "Mars Rock for Mom", Mindy does this when Jet reveals that he left behind her camera.
 * Failed a Spot Check: Carrot when he removes the spigot valve from the lemonade machine in "Astronaut Ellen Ochoa". Lemonade ends up flowing everywhere, but luckily, Sunspot serves lemonade to the neighborhood cats.
 * Failure Is the Only Option: No matter how many times Mitchell tries, he just can't successfully expose Jet, because in this universe, the identity of the Propulsions is apparently the Cassandra Truth.
 * Fainting: Several.
 * Carrot faints into Celery's arms when Jet mentions him in his song in "My Fair Jet".
 * Moonbeam faints after Sunspot flirtatiously winks at her in "Back to Bortron 7".
 * Jet faints after Zerk informs him that his parents will be assigned to another planet after their presentation in "Back to Bortron 7".
 * Mitchell faints at the very sight of Mindy in "What Goes Up...", after she sneaked up on him a second time.
 * He also faints at the sight of Mindy at the end of "Jet Shrinks the Kids".
 * He does this at one point in "That's One Gigantic Pumpkin, Jet Propulsion!".
 * Mitchell faints when Sunspot gets up close to him in "Our Sun Is A Star".
 * Sunspot faints on Dr. Skelley's lap in "The Tide is High" after discovering that the crab he has befriended has disappeared.
 * Fanboy:
 * Sean is a huge fan of Neil Armstrong, as well as Ellen Ochoa. "One Small Step" can best be described as Sean gushing over the Apollo 11 mission for 60 minutes.
 * Dr. Bergs is also an Ellen Ochoa fan. He even has a mug with her face on it.
 * Fangirl: Sydney is this to Commander Cressida.
 * Fantastic Racism: In "Whole Lotta Shakin'", Jet's cousin Zerk says that humans are not good at building. Keep in mind that this is a cartoon aimed at children.
 * Fantasy Helmet Enforcement: Whenever the kids ride their hover scooters or go-karts, they always make sure to wear helmets. The kids also always buckle up whenever they're about to go into space.
 * Fast-Forward Gag: In "Measure for Measure", while Jet is measuring how many astronomical units Neptune is from the Sun, a video progress bar appears. Sunspot appears behind the bar and fast forwards, speeding up the process.
 * Fatal Flaw: Sean's fatal flaw is that he fears cramped spaces, heights, and gets space-sick easily, but he must overcome these fears in time so he can achieve his dream of being an astronaut when gets older.
 * Fat Best Friend: Sean is the most overweight of the clique, but he doesn't really fit into any categories, as his main defining traits are his high intelligence and reluctance to go to space.
 * Feud Episode:
 * "Treehouse Space Station.", where the kids fight over who gets to use the treehouse for whatever reason.
 * In the episode, "Which Moon is Best?", Sean wants to be the first person to walk on a specific Moon. For the rest of the episode, Jet's parents argue over which moon Sean should walk on: Enceladus or Europa. They even have an argument in song. Luckily, they discover that both Enceladus and Europa are good moons in their own right.
 * Fictional Counterpart:
 * In a presentation, the creator, Craig Bartlett said that Commander Cressida is supposed to be a long running franchise like Doctor Who.
 * The Deep Space Array, where all the kids' parents work, is an Expy of NASA's Jet Propulsion Laboratory in Pasadena.
 * Fictional Video Game: In "Asteroids, Meteors, and Meteorites", Sydney and Sean play a video game called Astro Tracker, where to win, you have to identify and name certain asteroids.
 * Fiery Redhead: Jet, the energetic type.
 * Fish Out of Water: The Propulsions are aliens trying to fit into Earthie society.
 * Flying Saucer: The Propulsions have a minivan which turns into a flying saucer in space.
 * Foil:
 * Mitchell and Lillian. They are both friends of Mindy, and two of the most popular recurring characters. However, they are different in many ways. Lillian is gentle, innocent, easily excitable, and a bit air-headed. Mitchell is easily pissed off, prideful, anti-social, and smart for his age. Further more, Lillian is an Agent Mulder who is purely good, while Mitchell is a firm Agent Scully who hides his good traits. Despite this, the very little amount of interaction they had in "That's One Gigantic Pumpkin, Jet Propulsion!" seems to prove that they are on somewhat good terms with each other. Justified as Lillian is best friends with Mindy, while Mitchell seems to like her a bit, which means that they are going to end up hanging out.
 * Sean and Sydney. They are both friends of Jet and they are both his minders and kids that love science. Sean likes science facts and sometimes doesn't understand imagination being used in science. He is also more prone to panicking under pressure and, of the main characters, is the most prone to grab the Jerkass Ball (most noticeable in "Sounds Abound"). On the other hand, Sydney prefers science-fiction and using her imagination in science. She is quite calm and laid-back, and is also a motherly Nice Girl.
 * Dr. Rafferty and Dr. Bergs. They are both DSA scientists who are friendly and teach the kids various things about science. Dr. Rafferty is competent and is almost never used for jokes, while Dr. Bergs is a bit of a bumbling Big Eater who is often used for jokes, especially if it involves his coffee obsession. On the flip side though, Dr. Bergs has Hidden Depths - being related to Lone Star himself, while Dr. Rafferty has no depths to speak of. While there is her apparent All of the Other Reindeer childhood where she "felt like an alien", it is only implied and has never been mentioned since then.
 * Mr. Peterson and Carrot. Both are somewhat goofy fathers. Carrot embraces his silliness and is usually a nice dad, but isn't above being stern to Jet (like in "Chore Day"). Mr. Peterson, on the other hand, treats the most minor of things as Serious Business (such as mini-golf and the communications satellite not working) and almost always lets Mitchell get away with stuff.
 * Food as Bribe: In "Pet Sounds", the kids realize that they can use dog treats to motivate Cody to do tricks.
 * Forgetful Jones:
 * The Propulsions always forget not to tell people that they come from Bortron 7.
 * Jet, who always needs to Sean to teach him the Scientific Method over and over.
 * A Running Gag in "Mars Rock for Mom" is Jet leaving his things behind and forgetting where he put them. First, he forgets his jacket. Next, he forgets his wallet. Then, he devises a plan to get Jet 2 to pick up after him so he doesn't leave his stuff behind, only to realize that he left Jet 2 on Mars. Finally, Jet leaves behind Mindy's camera. Luckily, the camera was inside Jet 2's stomach compartment.\
 * For Halloween I Am Going as Myself: In the Halloween special, Jet dresses up as an alien. And gets away with telling people he is from Bortron 7.
 * Foreshadowing: Plenty of examples.
 * In "Backyard Moon Base", the kids find the house remote. They press some of the buttons on it, which causes the house to fly in the air, unbeknownst to them. In "Back to Bortron 7", it is revealed that the Propulsion house is actually a starship turned house. Pressing the remote converts the house back to a starship. No wonder Carrot was especially freaked out when he saw the house flying in "Backyard Moon Base".
 * In "Project Pluto", Carrot at one point utters "little frozen Pluto". And in the planetarium show in "Visit to the Planetarium", the aforementioned show refers to Pluto as "dear little frozen Pluto". Both foreshadow the song "Dear Little Frozen Pluto" from "From Pluto With Love".
 * Tons of examples in "Back to Bortron 7":
 * During the first song "Is Your Planet Like My Planet?", one of the lyrics is There's no planet like my planet, which foreshadows the song aptly named "There's No Planet Like My Planet".
 * Somewhere at the beginning of the movie, Carrot and Celery are practicing their PowerCube presentation. Their lines are It's not too hot, and not too freezing / And is suitable for breathing / Not too big / And not too small / And planet Earth is what its called!. Later, during the Just Add Water song, the cast sing these lines: Plus it's not too hot, and no, it's not too freezing / Add to which its atmosphere is suitable for breathing / It's really not too big / And really not too small / And planet Earth is what its called!
 * At one point, Jet says "What do you call those things in cities that shoot water in the air?", and Sydney and Sean respond with "Fountains.". Later, during "Just Add Water", the song stops so Celery can asks what they call those things in cities that shoot water in the air. Guess what Sydney, Jet, and Sean respond with.
 * In the show credits, doodles of the characters are scattered throughout. However in the credits for "Back to Bortron 7", at one point we see Mindy in a space suit, which foreshadows the fact that Mindy turned five in season 2, and is now able to go to space.
 * In "Asteroid Belt Space Race", Eggplant's lyrics in the song "Space Racin'" foreshadow to her having anti-gravity fluxinators installed in her saucer.
 * Eggplant: Well, boosters and carbifonators may sound good, but I've got something special sittin' under my hood.
 * In "Bortron Leprechaun", Carrot's can of green paint falling on Sunspot foreshadows that the leprechaun was actually Sunspot all along.
 * In "One Small Step", during the song "Super Saucer", the kids sing about how it's easy going to space, but hard getting back. Later, the gang has trouble getting back to Earth from the moon because Sydney used the landing gear crank to fix the saucer. The gang ends up using a parachute and crashing into Little Dipper Lake, where they almost drown but Mitchell rescues them.
 * In that same special, Jet 2 presents Sydney with a mysterious object that Sydney thinks is a robot arm. She asks Jet 2 if they will need it in the future, and he says no, so Sydney uses it to fix the saucer. It turns out that the "robot arm" was the landing gear for the saucer. Without the landing gear, the landing will be difficult. So, the kids end up using a parachute and crashing into Little Dipper Lake back on Earth instead.
 * At the end of "Back to Bortron 7", Zerk asks Jet when he can come visit Earth, which is foreshadowing to Zerk visiting Earth in "Zerk Visits Earth".
 * Four Philosophy Ensemble: The main cast of kids fit into this.
 * The Cynic: Sean. He's usually the most logical of the group and doesn't always agree with Jet's ideas. However, this is downplayed, as Sean is not as mean as most examples.
 * The Optimist: Jet. He's a Genki Guy who always looks on the bright side of things and sees the good in everyone.
 * The Realist: Sydney. She usually meditates between Jet and Sean's differences and balances them out, often acting as the Team Mom towards them.
 * The Apathetic: Mindy. Being a little kid, she just doesn't care either way.
 * If Mitchell is involved, then he'll be either The Cynic, The Apathetic, or The Conflicted (he's not only morally complicated, but he was also insecure about fitting in with the group).
 * Four-Temperament Ensemble: Jet (Sanguine), Sean (Melancholic), Sydney (Phlegmatic), and Mindy (Choleric).
 * Free-Range Children:
 * The children are always doing stuff on their own, such as building a treehouse. Craig Bartlett even stated that the kids' adventures are supposed to be similar to his childhood adventures where the kids would just run around without adult supervision.
 * However, the kids always have adult supervision in outer space.
 * Taken Up to Eleven in "One Small Step", which marks the first time that the kids go to space by themselves. However, they got Carrot and Celery's permission to go by themselves.
 * Freeze-Frame Bonus: Plenty in "Back to Bortron 7". At one point in the movie, Mindy wakes up at midnight and tries to make Jet 2 put the hologram of the house back, and Jet 2 instead projects many other holograms that can only be seen if you pause. The holograms include Sean standing with his hands folded, that same hologram with Sean's mouth closed, a hologram of Sydney, a hologram of Sean in his space-suit, the weather balloon from "My Fair Jet", a hologram of Mitchell cackling, a hologram of Sunspot in a Greek outfit from "Jet's Time Machine", a hologram of Mindy in her pajamas on the flying saucer, and a hologram of the pineapple jack-o-lantern from "Jet's First Halloween".
 * Freeze Ray: Sunspot builds one for Mindy in "Mindy's Ice Rink".
 * The Friend Nobody Likes: Zerk, mostly because he was a racist bigot to the Earthies in the past, and he is quite irritating. The other kids only hang out with him because he's Jet's cousin. Everyone is actually glad when he leaves at the end of "Zerk Visits Earth".
 * Friendly Tickle Torture: In "Satellite Selfie", Jet and Sydney tickle Face 9000. Apparently, computers are ticklish.
 * Freudian Trio:
 * Sydney is the Id. Unlike Sean, Sydney wants to become a successful science fiction author and is more into science fiction and Greek mythology. She is also more emotional, kind, and loving than any of the group.
 * Sean is the Superego. Sean is studious and smart, and wants to grow up to be a great scientist and lead the first human mission to Mars. Sean is also concerned about his grades most of the time and uses the Scientific Method, as well as logical reasoning, to solve problems. Due to this, he has a terrible imagination.
 * Jet is the Ego. While Sean and Sydney are polar opposites, Jet is one of the sole reasons why they hang together and the arrival of Jet pretty much brought them together. Jet is talented at acting, singing, and dancing, and is curious about everything, especially Earth. Jet is also kind and generous, and always has a positive attitude and great leadership skills.
 * The younger kids trio fits into this as well:
 * Lillian is the Id. She's the most emotional and loving of all of them, and she easily believes that Halloween is magical.
 * Mitchell is the Superego. Mitchell is nerdy and tries to use logic and reasoning when dealing with strange things. He's also a bit of a jerk.
 * Mindy is the Ego. She's Lillian's best friend and Mitchell's (speculated) crush, which is why they both hang out with her. She easily balances them out.
 * Dr. Rafferty, Dr. Bergs, and Dr. Skelley end up forming one in "Astronaut Ellen Ochoa". Dr. Bergs is the Id, because he's the most emotional of the trio. Dr. Rafferty is the Superego, since she seems more composed than Bergs, though that's not saying much. Dr. Skelley is the Ego, being the middle point between the two and the most level-headed one.
 * Friendly Enemy: Mitchell is this to Jet and his group. Mitchell is rude to the group, but he can get along with Jet and Mindy sometimes.
 * Funny Background Event: In "How Come the Moon Changes Shape?", Carrot and Celery sing an amazingly sappy love song. While they're singing it, Jet and Sean are grossed out, and Sydney and Mindy punch them for disliking the song.
 * Gadgeteer Genius: Dr. Skelley, Sydney's mom. She knows all about robotics, engineering, and technology. She also holds a strong belief that robots are the future, and teaches the kids about the types of jobs robots have, like helping out at a grocery store, rescuing trapped animals during a flood, collecting comet dust samples, and exploring volcanoes on Mars. She even rebuilds Jet's robot clone, Jet 2, at the end of the episode and makes him into a Do-Anything Robot. Now that is awesome.
 * GASP: In "Sunspot's Sunspot", when Sunspot says "No, thank you", all the kids do a dramatic gasp.
 * Gender Equal Ensemble: Sydney is traditionally a boy's name.
 * Gender Equal Ensemble: In Jet's clique, there are two boys (Jet and Sean), and two girls (Sydney and Mindy), if one does not count the Team Pet Sunspot.
 * Genki Girl: Or rather, Genki Person -- Virtually every member of the Propulsion family.
 * Get a Hold of Yourself, Man!: The gang is usually this to Sean, who is usually apprehensive about going to space.
 * Giant Food: Using his Bortronian grow lamp, Jet grows a huge pumpkin in "That's One Gigantic Pumpkin, Jet Propulsion!"
 * Gilligan Cut: Happens in "Space Junk", where Sean says there is no way he is flying outside the saucer. In the next scene, he says he can't believe he's flying outside the saucer.
 * Girlish Pigtails: Mindy wears her hair like this.
 * Girls Love Stuffed Animals: Mindy and Lillian both have teddy-bears.
 * Girls Night Out Episode: "Commander Cressida Begins" mostly focuses on the female characters, namely Mindy, Sydney, Celery, and Dr. Skelley. On top of that, Celery takes only Sydney and Mindy to space to see Jupiter's moons, while leaving behind Jet and Sean.
 * Go Mad From the Isolation: Carrot undergoes a major Sanity Slippage in "Castaway Carrot" while stranded on the moon. He gets a twitchy eyelid at one point, attempted to farm pizza on the moon, and drew pictures of his family on rocks, and made out with the Celery rock.
 * Good News, Bad News: In "Sean's Robotic Arm", Jet delivers this in the form of "Good News, Better News". The "Good News" (which is actually bad news) is that Jet's broken Bortronian robot arms have been sent back to Bortron 7 for parts, which will take a week even with expedited intergalactic shipping. Then Jet reveals that there are no better news.
 * Good Parents:
 * Jet's parents are very kind, tolerant, and encourage the children in their science exploration, and are always happy to take them into space.
 * Dr. Rafferty and Dr. Skelley are also excellent parents.
 * Gosh Dang It to Heck: In "Who Messed Up The Treehouse?", Jet says "It's those darn squirrels again!".
 * Graceful Ladies Like Purple: Part of Lillian's dress is purple. Fitting the "graceful" part, she's a Girly Girl and she also likes to do gymnastics, even doing a somersault with ease.
 * Graceful Loser: In "Kid-Kart Derby", Jet ends up losing the derby, but takes this in stride and is glad that he had fun in the race anyways. This contrasts with Mitchell's reaction to winning the derby, where he's happy about it at first, but sad because no one's cheering for him.
 * Gratuitous Disco Sequence: In "Moon Circus", part of Carrot's famous flip is to do a disco dance, complete with techno music.
 * Gratuitous French:
 * In "Sunday Drive", Celery briefly practices French and says "Allons à Mars", which is French for "Let's go to Mars".
 * In "Sunspot's Sunspot", Celery says "Bon appetit, as the French Earthies say".
 * Great Big Book of Everything: As of season 2, a new element of the series is "The Big Book of X", an In-Universe book series that will sometimes be brought up by Sean, and will always relate to the topic of the episode. There's "The Big Book of the Sun", "The Big Book of Birds", "The Big Book of Eclipses", "The Big Book of Clouds", and possibly even more.
 * Green-Eyed Monster:
 * In the episode "Jet 2", Jet gets jealous of his robot clone, Jet 2, because Sean and Sydney are playing with the robot and not the real Jet.
 * In "Back to Bortron 7", Face 9000 is extremely salty that the Propulsions have chosen the PowerCube for their presentation and not him. He does get to help with the presentation at the climax, though.
 * In "My Three Suns", Face was jealous that the kids found Sunspot to be funnier than him.
 * Groundhog Day Loop: Happens in "Jet's Time Machine", where the kids go back in time, but are stuck in an endless loop and keep missing the meteor shower. However, once they correct their mistakes, they break out of the loop and are able to watch the meteor shower.
 * Groupie Brigade: Mitchell tries to invoke this in "Kid-Kart Derby" by asking anyone if they want autographs from him after he won the race, but fails.
 * Group Hug:
 * Jet, Sean, and Sydney share one in "Back to Bortron 7".
 * Jet, Sean, Sydney, Mindy, and Sunspot share one at the end of "Racing on Sunshine".
 * Jet, Sean, and Mindy share one when Mindy and Sean find him in "One Small Step".
 * Hair Decorations: Lillian has a big pink bow in her hair.
 * Hair of Gold: Bergs has blonde hair, and is very kind and friendly.
 * Halloween Episode: "Jet's First Halloween" and "That's One Gigantic Pumpkin, Jet Propulsion!".
 * Handshake Substitute: In "Detective Mindy", the kids put together pieces of evidence and discover that Mr. Peterson had knocked his wife's sunglasses down with his glass of water, and then Mrs. Peterson vacuumed them by mistake. Jet and Sean then proceed to do a fist bump.
 * Happily Married: Carrot and Celery, even having a love song dedicated to them.
 * Hartman Hips: Jet's aunt, Eggplant, has these.
 * Hates Baths: Sunspot loathes taking baths, as shown in "Uncle Zucchini Babysits" and "Bortron Leprechaun".
 * Head Desk: Sean does one in "Fact Or Fiction?".
 * Here We Go Again: At the end of "Sean's Robotic Arm", Cody runs off with Sydney's Commander Cressida figure and puts it in his hiding spot. The kids use the robotic arm to take it back.
 * The Hero: Jet, of course.
 * He Went That Way!: In "What Goes Up...", Mitchell tries to chase after Jet's flying saucer. Mindy tells him that the flying saucer went to the right. Mitchell assumes if Mindy says he's going to the right, then he must be going to the left. Of course, Jet didn't actually go left.
 * Hey, Let's Put on a Show:
 * The synopsis of "Holidays in Boxwood Terrace", but without monetary gain in mind.
 * This is also the plot of "A Star is Born".
 * Hey, That's My Line!: In the episode "Mini-Golf at the DSA", Sean says this when Mr. Petersen scores a hole-in-one and says Sean's catchphrase "Booyah, science!".
 * Hidden Depths:
 * Sunspot is revealed to have many talents. He can pull objects out of Hammer Space, and can play several instruments, including concertina and pan-pipes.
 * Jet has these, too. He turns out to be very handy with tools, and a great musician.
 * Carrot is revealed to be a great cook, and "Castaway Carrot" reveals that he taught himself ballet.
 * "Eye in the Sky" reveals that Mitchell is an expert on the weather.
 * "That's One Gigantic Pumpkin, Jet Propulsion!" reveals that Dr. Skelley has a knack for gardening.
 * "Freebird" reveals that Dr. Rafferty likes studying birds.
 * Sean is a drummer and Sydney is a pianist, as shown in "Potatoes on Mars".
 * In "Mars Rock for Mom", Jet 2 is revealed to have adapted to the Mars environment when he was stranded there, and also learned how to play checkers. Meanwhile, Dr. Rafferty is revealed to have a rock collection.
 * Sydney is shown to have a real knack for engineering and mechanics. She builds her own robot in "Sydney 2", and fixes the saucer in "One Small Step".
 * Hidden in Plain Sight: The show thrives off of this trope. The Propulsions coincidentally look like humans,
 * Hiroshima as a Unit of Measure: In "Measure for Measure", the kids decide to make a scale model of the solar system in the yard. They use Sunspot as an astronomical unit.
 * Hoist by His Own Petard: An odd example. In "Kid-Kart Derby", Mitchell cheats by installing an ion drive into his kid kart, but then when he starts to use it, it doesn't work. Jet then informs him that ion drives only work in the vacuum of space. Mitchell still wins the derby, however.
 * Holding Hands:
 * In "Back to Bortron 7", Carrot and Celery hold hands as they're about to enter the Intergalactic Travel Writers' headquarters.
 * In "That's One Gigantic Pumpkin, Jet Propulsion!", Mitchell, Mindy, and Lillian all hold hands as they go trick-or-treating.
 * Hologram: Ever since "Back to Bortron 7", holograms have been used egregiously on the show. They have been used to deceive the neighbors, show maps of the galaxy, take online classes, and more.
 * Hologram Projection Imperfection: Played straight in "Back to Bortron 7". Jet 2 has to project a hologram of Jet's house, while the real house converts back into a starship for a trip to Bortron 7, so Mitchell doesn't get suspicious. However, Jet 2 has a hard time keeping the hologram stable, as it keeps glitching. Towards the end of the movie, it disappears completely, which gives Mitchell an opportunity to expose Jet (which luckily fails).
 * Hook Hand: Lillian wears this as part of her pirate costume in "That's One Gigantic Pumpkin, Jet Propulsion!".
 * House Husband: While Celery is always taking the kids to space, Carrot stays home and does things like cooking.
 * Huddle Shot: In "Back to Bortron 7", this happens while Jet, Sean, and Sydney are thinking up ideas to improve the presentation.
 * Human Aliens: The Propulsions are aliens, but they look like humans. This helps them blend in on Earth.
 * Humans Through Alien Eyes: Jet and his family do not seem to get the Earthlings' behaviors and vocabulary, often using them the wrong way. Once, Carrot was shown mowing the roof.
 * Hypocrisy: In "That's One Gigantic Pumpkin, Jet Propulsion!", Mitchell chastises Jet for singing to his pumpkin, but Mitchell himself creepily talks to his own pumpkin and calls it his "precious". Er...you okay, Mitch?
 * I Always Wanted to Say That: Sean says this after saying "There's not a moment to lose!" and "Come on Zerk! Back to the house! And step on it!" in "Back to Bortron 7".
 * "I Am" Song:
 * "Bortronian Is What I Am", written and sung by Jet himself in "My Fair Jet".
 * In "Lone Star", there is "Lone Star", sung by Jet, playing the titular Lone Star.
 * Mindy has "My Name is Mindy".
 * I Ate What?: Mindy, Sean, and Sydney have this sort of reaction in "Satellite Selfie", where they discover that the cookies that they ate were made from a full cup of minced garlic and rutabaga.
 * I Can't Believe I'm Saying This: In "Back to Bortron 7":
 * Sean: I can't believe I'm saying this, but, let's go to Bortron 7.
 * Idiosyncratic Episode Naming: Sometimes. Some episode titles are based around a question ("How Come the Moon Has Craters?")
 * Idiosyncratic Wipes: The show often uses spinning silhouettes of Sunspot for transitions.
 * Idiot Ball:
 * Jet gets passed this in "Mindy's Weather Report". In that episode, Mindy tells the gang that a storm is on Saturn, and Jet believes that there's a storm in Boxwood Terrace, and tells all the neighbors (including the Petersons) to prepare, despite the number of times Sean, ** Sydney, and Mindy try to tell Jet that the storm is on Saturn. When the gang goes into space, they see the storm on Saturn and Jet says: "Why didn't you tell me?" with Sean and Sydney in annoyance.
 * Mindy gets passed the idiot ball in "Galileo, Galileo!", where she believes that the sun orbits the Earth, despite the fact that in "Round and Round", she portrayed the Sun and saw that the solar system revolves around the sun, not the Earth.
 * Mindy grabs the idiot ball in "Our Sun Is A Star!". In "How We Found Your Sun", she learned that the sun is a star, but in this episode, she's somehow convinced that the sun isn't a star.
 * I Just Want to Have Friends: This is most likely Mitchell's Freudian Excuse for why he acts the way he does. It is revealed in "Holidays in Boxwood Terrace" that he is really a lonely kid and he acts like a jerk to hide it.
 * Imagine Spot:
 * Happens in "More Than One Moon". There are several imagine spots in "Backyard Moon Base".
 * In "Sean's Robotic Arm", Sean has one where he's on the moon dressed as Neil Armstrong and Jet, Sydney, and Mindy are in their regular space-suits. Sean gives them a motivational speech and convinces them that they should combine the various parts together to make a robotic arm to retrieve Neil.
 * In "Astronaut Ellen Ochoa", the kids and Ellen have one where they fly in space and go to the International Space Station.
 * In "My Three Suns", Sean, Sydney, and Jet all have imagine spots about what it would be like to live on a planet with 3 moons. Sean imagines never being able to sleep, Sydney imagines having too many birthdays, and Jet imagines playing shadow tag and then being unable to find anyone.
 * I'm Not Here to Make Friends: In a non reality show example, in the Christmas Episode, Sean asks Mitchell if he wants to join them, saying that "you are our friend", but Mitchell claims "he doesn't do friends". Of course, he's lying.
 * Implied Love Interest: Mindy and Mitchell are heavily implied to have crushes on each other, in episodes like "What Goes Up..." and "Kid-Kart Derby" where Mindy constantly sneaks up on Mitchell and and even tried to ask him out on a date in the latter episode. Mitchell acts abrasive towards her in return, especially in "Mindy's Mystery", but "Solar System-Bake Off!" and especially "Detective Mindy" (where Mitchell apparently proposes to her at the end of the episode) seem to show that Mitchell does care about Mindy. However, it hasn't been confirmed in the show at all.
 * Impossible Shadow Puppets: In "My Three Suns", the kids learn how to make some very hard shadow puppets towards the end of the episode.
 * Improbable Piloting Skills: In "Back to Bortron 7", Celery assigns Sydney the role of the co-pilot of the Mothership. Sydney figures out how to steer the mothership almost instantaneously. This continues into the regular season 2 episodes as well. In "Souped Up Saucer", Sydney becomes the Wingman of the flying saucer, proving herself to be just as skilled a pilot as she was in "Back to Bortron 7".
 * Incoming Ham: "In the quiet I hear the stars, calling to me from on HIIIIIGGGHHH!!!"
 * Incredible Shrinking Man: This is the plot of "Jet Shrinks the Kids", where Jet shrinks himself, Sydney, Sean, and Sunspot to become Mindy's size. Things go awry, however, and they become the size of mice. Mindy spends the episode trying to reverse the shrink ray, while Jet, Sydney, Sean, and Sunspot try to evade Mitchell and Cody.
 * Incredibly Lame Pun:
 * Face 9000 makes one in "Mindy's Meteorite Stand": "And Sean's right, the proper tests will help you discover if your rock is meteorite or meteor-wrong!"
 * He makes another one in "Eye in the Sky": "I couldn't tell weather or not you needed my help!"
 * Mindy makes one in "You Can Call Me Albedo" after having just learned what albedo is. "Albedo right there!"
 * In "Our Sun Is A Star!", when Jet lifts his sunglasses up and down so it appears that Mitchell is turning orange and then back to his normal color, he says this: "Orange you glad you're not permanently orange?".
 * I Need to Go Iron My Dog: Whenever Mitchell is about to be caught spying, he always makes flimsy excuses to leave.
 * In "Kid-Kart Derby", when Mitchell overhears Sydney while he's in Jet's garage, Mitchell says that he thinks he left the hose on, or the lights.
 * In "That's One Gigantic Pumpkin, Jet Propulsion!", when Jet and Sydney catch him spying on them, he says he has to go water his dumplings. Later, when he's with Lillian and Mindy, he says that he has to go do something completely different from what they're talking about.


 * Innocent Aliens: The Bortronians are very kind-hearted.
 * Innocently Insensitive:
 * Jet means well, but can sometimes do some rather careless things when helping others.
 * Celery is also this. Best exemplified in "My Three Suns", where she doesn't let Sean go to the bathroom in the name of learning.
 * Interspecies Friendship: The humans Sean, Sydney, and Mindy are best friends with the alien Jet.
 * Interspecies Romance: In "The Tide is High", Sunspot comes a little too infatuated with a crab at the beach.
 * Intrigued by Humanity: The Propulsions are very interested in humankind, or as they call them, "Earthies", and are always trying to learn their customs.
 * In-Series Nickname: Sean has "Sean-zo", an Affectionate Nickname coined by Jet in season 2.
 * Insistent Terminology:
 * Sean's Neil Armstrong figure is an "action figure", not a "toy".
 * In "My Three Suns", Face 9000 demands that the kids call him "Funny Face".
 * Instant Costume Change:
 * Whenever the group goes into space, Sean and Sydney instantly change from their regular outfits to their space suits.
 * In "Sean's Year In Space", Sean changes into his space suit when he tries to live in the treehouse for a year very quickly.
 * In Touch with His Feminine Side:
 * Mitchell, perhaps? In a leaked image of "Holidays in Boxwood Terrace", he is shown wearing a lavender dress. Judging by the reaction on his face, he seems to be happy about it.
 * Also, in "Try and Try Again", Mitchell seems to have no qualms about wearing Mindy's lucky helmet...which has rainbows and unicorns on it.
 * Carrot too. Carrot is a stay at home dad, and he likes to cook. He is also revealed to like ballet in "Castaway Carrot", and he briefly wore a pink scarf while admiring himself in a mirror in the same episode.