"One needs only to look upon the once-green planet of Mars to understand the full scope of the devastation the Rüstov leave in their wake."
How do you know that the problem the heroes are dealing with are a real threat? Because the threat in question hit another planet first, and they're coming for the plot-relevant planet next. If that next planet is Earth, see Earth Is the Center of the Universe
Compare Earth That Was
and Phlebotinum Killed the Dinosaurs
, for when the crisis struck closer to home eons earlier. Usually the result of Planet Looters
, a Planet Eater
, or Aliens Are Bastards
. Can result in an Earth-Shattering Kaboom
A special dramatic mention should be made for plots that use Mars in the place of the planet that was previously destroyed. Since Mars is Real Life is well-understood to be barren and lifeless, it already gives a very chilling demonstration of what the threat is capable of, as well as additional chills because it happened so close to us.
Yes, a certain former planet
qualifies for this trope as well. It's in our solar system, it counts.
Anime and Manga
- In Magical Girl Lyrical Nanoha A's, the Book of Darkness is said to have destroyed countless planets before finding its way to Earth, and so Team Nanoha embarks on a quest to locate and stop it.
- As with the movie example above, in Fantastic Four, the planet-eating Galactus came to Earth a few times to devour it after spending centuries feeding on other planets without much trouble.
- In Fantastic Four: Rise of the Silver Surfer, after the Surfer inadvertently interrupts Richard and Sue's wedding and nearly causes a helicopter crash, Richard discovers energy signatures in the cosmos matching the Surfer that correlate to destroyed planets.
- The 2009 Star Trek movie showed the planet Vulcan being destroyed, and then headed for Earth to do the same.
- Alderaan from Star Wars is destroyed to demonstrate how evil the Empire is and the powers granted to them by the Death Star.
- A throwaway line in the first Jack Blank book shows that the planet of Mars once was as green as Earth, and that the reason it's as barren as it we know it is because the planet-consuming Rüstov already finished with it, and they are presently attempting to invade the Earth.
- Robert A. Heinlein's Stranger in a Strange Land has a brief passage from the perspective of the Martians who adopted Valentine Michael Smith. From their perspective he's evaluating humanity, and if they don't measure up, well ... Jupiter used to be the sixth planet and Mars was always fourth.
- In the Star Trek: The Original Series episode The Doomsday Machine, the titular weapon has already annihilated a solar system and all but two planets of another by the time the Enterprise gets on the scene. It's set on a course through the most densely populated section of the galaxy to sustain itself.
- Transformers: One ad for a Unicron model goes, "He devours entire worlds. His name is Unicron. And he's heading ... for Earth."
- The Clue Finders: Mystery of the Missing Amulet. The games eponymous MacGuffin, the Amulet of Life, was responsible for completely reducing the planet Millenia into a dying wasteland. At the end of the game, the evil sorceress Malicia says that once she finishes off Millenia with the Amulet, she's going to drain life from the Cluefinders' home planet, Earth, next.
- Metroid Prime:
- Inverted in Metroid Prime 3: Corruption. The planet Norion is doomed from the start from a looming Phazon leviathan impact, but Samus manages to save it at the last minute. Later on it's revealed that the other planets in the system suffered a Phazon leviathan impact while she was in a coma and are already showing signs of corruption, so Samus goes to those planets to stem it.
- Played straight if the planets in the earlier titles, Tallon IV in Prime and Aether in Echoes would be any indication regarding the fate of the Phazon-corrupted planets in Corruption. The difference being that Samus already saved those planets and they're on their way to recovering so she knows she could save the others.
- In Crash Team Racing, it's revealed that Nitros Oxide is the cause of the barren wasteland on Mars: the inhabitants on the planet failed to defeat him at racing and thus get decimated. He threatens to do the same on Earth (by making the planet a parking lot and slaving all its inhabitants) if they failed to defeat him at racing, too - setting up the story.
- In Quentyn Quinn, Space Ranger, a Planet Eater eats a system's outer planet, moons first and then the main world a week later. Then it ate the life-bearing planet's moon, and that was a week ago...
- In the Ben 10: Alien Force episode "Fool's Gold", mischievous but harmless aliens come to a village every 17 years where they eat massive quantities of popcorn and defecate solid gold. When the town's mayor gets greedy and kidnaps one, he gives the alien a steak, causing the alien to grow into massive size and defecate unstable uranium. The alien's friend tells Ben that Mars "used to be called The Popcorn Planet" before his kind came there.
- When the Brains go on a rampage in Futurama, Hermes points to each destroyed planet on a flat star map and notes that each planet forms a straight line that points directly toward the Earth; precisely the planet that the Brains attack next.
- The first episode of the Justice League cartoon displays an invasion of aliens coming to Earth. These aliens previously had taken Mars, leaving the Martian Manhunter as the sole survivor, who comes to Earth to warn the planet and help form the Justice League to fight them off.
- In the Dexter's Laboratory "Dial M for Monkey" shorts Rasslor, the universe's greatest wrestler goes searching for worthy opponents on inhabited planets. If no one can beat him he destroys the planet.
And so my quest has brought me to this timid little planet you call Earth, so, terrestrial heroes, can one of you quench my thirst for the divine conflict, the supreme struggle? Or will your planet be doomed to the same fate, that has befallen so many.