When the Planets Align

"''"When the moon is in the seventh house ''And Jupiter aligns with Mars ''Then peace will guide the planets And love will steer the stars""

- Hair (theatre), "Aquarius"

Something in the plot depends on some stars or planets lining up in a particular order at a certain time (an event known in astronomy as syzygy). Often doomsayers claim this will be the cause for The End of the World as We Know It, whether by breaking the tectonic plates, causing a shift of the poles, changing the Earth's rotation..., or introducing the Eldritch Abomination.

When it overlaps with Significant Birth Date, it can occur in the Backstory and still complicate the plot; this can produce The Chosen One or the Big Bad.

Compare with:

 * Celestial Deadline: where you can use these sorts of events.
 * Total Eclipse of the Plot, a Sub-Trope which has several examples, e.g. Isaac Asimov's Nightfall and the film Pitch Black.
 * Vicious Cycle, because these alignments tend to occur at regular intervals. Example: The Dark Crystal (Great Conjunction of suns).
 * Artistic License Astronomy: some examples fall into this category.

Contrast with:

 * A Year and a Day, where the countdown is not to some specified event but is tied to the passage of a fixed length of time.

Film

 * In Highlander the Source, the entire UNIVERSE-- every single celestial body from moons to planets to stars, and ALL OF THEM IN EVERY GALAXY-- comes into alignment, all focused on Earth. Even non-scientists and children knew better, but that didn't stop the writers.
 * Teenage Mutant Ninja Turtles (2007): the portal opens when stars line up.
 * Hercules: the Titans can only be freed when the planets line up.
 * The Final Conflict. The alignment of three stars creates the second Star of Bethlehem, a sign of the Second Coming of Christ.
 * Tomb Raider. A magic item that can be used to control time can only be accessed during a planetary alignment that occurs once every 5,000 years.
 * The Dark Crystal involves a triple-sun alignment called the Great Conjunction.
 * 2012 vaguely waves at this, with the Critical Research Failure of another planet visible from Earth's orbit and Jupiter visible from Saturn, but apart from Woody Harrelson's free-associating conspiracy theorist, it doesn't come up again.
 * In The Scorpion King, the villain will allegedly become invincible when the Moon is in "the House of Scorpio".

Literature

 * 5/5/2000, ICE: The Ultimate Disaster claimed that on the title date a planetary alignment would cause catastrophic disaster on Earth.
 * Robert Heinlein's Farmer in the Sky featured a dramatic alignment of the moons of Jupiter which the protagonists watched from Ganymede.
 * In Kushiel's Mercy, the Carthaginians take advantage of an astrological event to put a spell on the entire city.
 * One of the stories in Star Trek: The Brave and The Bold involves a Bajoran prophecy suggesting Bajor will be at peace when all the planet’s moons fully align. The bitter old terrorist Orta seeks to use a powerful artifact he’s unearthed (created by Sealed Evil in a Can Malkus) to artificially move a moon and fulfil the prophecy early. Of course, he doesn’t actually want peace - he’s just using the prophecy as a ploy to start a conflict with the Federation.
 * In the Cthulhu Mythos universe by H.P. Lovecraft and others, there are many references to how the Great Old Ones will return "when the stars are right".
 * One of the lesser Dragonlance novels featured a portentious lunar alignment between the white, red, and black moons of Krynn, known as the "Night of the Eye".
 * The Traveller in Black makes his periodic journeys when a certain array of four planets comes into alignment.
 * Two alignments of the seven planets play a major role in the timing of the third book of the Septimus Heap series.

Live Action TV
"Angus Deayton: This is the prediction that Jupiter and Saturn will align with Mars, Venus, and Mercury in the year 2000, which will cause flooding, earthquakes and tidal waves. The planetary alignment will cause gravitation forces from the Sun to... Paul Merton: No, it won't! Patrick says it won't! Ian Hislop: There isn't a lot of point getting an astronomer on if you're just going to read out a load of balls! Paul Merton: Ian, the correct term is spheres."
 * The X-Files episode "Syzygy". An alignment of Mercury, Mars and Uranus may have something to do with several murder cases in a small town.
 * The MacGyver story Lost Treasure of Atlantis features this. For some reason, the planets are visible, to the point where they would actually collide with each other.
 * Astronomer Sir Patrick Moore appeared on Have I Got News for You at a time when an impending alignment of the planets was being hyped in the tabloids as a catastrophe. Angus Deayton gave him pieces of fruit to represent the planets and kept referring back to the rumors, even though what Moore was demonstrating with the fruit was that absolutely nothing was going to happen.


 * On another occasion, Sir Patrick announced on radio that a rare alignment of the planets would temporarily reduce the Earth's gravitational pull, as people could discover by jumping up and down. Several listeners called in to confirm this, one man claiming that he had bumped his head on his ceiling. The fact that the broadcast went out on April Fool's Day seemed to have escaped their notice.
 * The first half of Rescue Sentai Go Go Five had the Saima preparing for the planets to line up into the Grand Cross so they can bring back Grandienne. This carried over to their American counterparts in Power Rangers Lightspeed Rescue.
 * In episode two of Tensou Sentai Goseiger, Hyde is told the Gosei Angels can only return to their own world during a solar flare that occurs once every 200 years. Unfortunately, at that time they are fighting a Monster of the Week, and he decides to remain on earth instead to protect the earth with the others.
 * In the Doctor Who serial "The Masque Of Mandragora", Hieronymous invokes this. He even appears to believe it.
 * The series four finale ("The Stolen Earth"/"Journey's End") had twenty-seven planets stolen from their home systems and placed in perfect alignment by the Daleks to create an engine to be used to amplify the "reality bomb" that would destroy every universe in all of reality.
 * Star Fleet has all the planets in Earth's solar system aligning at the end of the year 2999 for the dawn of a new millenium.

Tabletop RPG

 * Dungeons and Dragons supplement Treasure Maps, adventure "Sign of the Times". Every 700 years during a specific astrological conjunction of planets, moons and stars the king of a desert empire will fall ill and die, and his son will take his place. The new king will become evil and cruel, raising taxes and invading other countries. Natural disasters (famine, pestilence and drought) will ravage the land.
 * In Rifts, The Great Cataclysm occurring during (and in part because of) a rare conjunction of the planets. It caused the Ley Lines to surge with power. This combined with a couple other factors upset the Earth's magical balance, causing The Coming of the Rifts.

Theatre

 * Hair references the trope during the song "Aquarius": "When the moon is in the seventh house and Jupiter aligns with Mars/then peace will guide the planets and love will steer the stars"

Video Games
""When the moon is in the seventh house, and jupiter aligns with mars...then peace will guide our planet and love...? Naw, it'll never happen.""
 * Subverted in Crash Bandicoot 2: Cortex Strikes Back. Crash's goal is to gather Crystals so Cortex can use them to safeguard the world from a planetary alignment..
 * The aforementioned song from Hair is referenced in Quest for Glory II, by the astrologer:


 * The World Ends With You: When six darklit darklit planets align...
 * Pious Augustus of Eternal Darkness is counting on the planets aligning to channel enough power to summon his Ancient into the mortal world. He's been waiting for two millenia for this event when the game opens.
 * The Grand Cross planetary alignment is a major part of the plot of Persona 2: Innocent Sin. In Eternal Punishment, it's become a minor background element whose only significance is that absolutely nothing of note happened during it...

Web Comics

 * Wapsi Square: You know what happens in 2012 when the Mayan calender runs out? Groundhog Day Loop!
 * Eerie Cuties: A vampire born on the first Sunday after the first full moon after the vernal equinox does not drink blood. (A.k.a. Easter)
 * Dork Tower lovecraft is

Western Animation
"Optimus Prime: And it was written in the Covenant of Primus that when the forty-seven spheres align, a perpetual conflict will culminate upon a world forged from chaos; and the weak shall perish in the shadow of a rising darkness."
 * The Rocko's Modern Life episode "Born to Spawn." Filbert's breed of turtle has a mating season that occurs when all the planets are in alignment, and is hypnotically irresistable. In the end, Heifer has a similar problem starting when all the fast food restaurants go into alignment.
 * Don't think too hard about the Heifer thing, given that he's a steer.
 * In Teen Titans it's said that Trigon could only arrive on Earth when the planets align. We don't actually get to see any planetary alignments, but there is a freaky eclipse going on simultaneously.
 * Major plot points of the 3/4 year storyline of Avatar: The Last Airbender include a
 * In My Little Pony Friendship Is Magic, Nightmare Moon is said to return on the longest day of the thousandth year, when the stars will aid in her escape.
 * In Teenage Mutant Ninja Turtles (2003), the underground city's crystal technology is recharged completely with the coming of the planetary alignment, which allows the city's inhabitants to revive themselves.
 * A teaser for the second season of Transformers Prime ties such a prophecy with :


 * Somewhat justified (or Hand Waved, depending on your point of view) by the fact that gravitational forces from those planets were somehow acting on Unicron, causing him to wake up.

Religion and Mythology

 * It has been suggested that the star which guided the Wise Men to Jesus' manger was not actually a star, but a particular astronomical alignment.

Real Life

 * Voyager 2's trajectory took it past Jupiter, Saturn, Uranus and Neptune, due to a planetary alignment that only occurs once every two or three centuries.
 * The Jupiter Effect was a 1974 book that predicted that a planetary alignment on March 10, 1982 would have disastrous effects on Earth. (It didn't.)
 * On December 21 2012 (or is it 2011?) (it's every year, inasmuch as it happens at all: the galactic centre (Saggitarius A*) is seven degrees away from the ecliptic) the Earth, Sun, and center of the Galaxy line up, which some people believe will have various consequences.
 * If the small asteroid Apophis passes through the keyhole (an imaginary region of space), gravitational physics models predict it will hit the earth in 2036.
 * The "Jovian-Plutonian Gravitational Effect" hoax of 1976 by the British astronomer Patrick Moore. The guy stated to radio listeners that an alignment of Jupiter and Pluto on 9.40 am, April 1, 1976, will noticeably reduce gravity on Earth. Many believed.