What if all Earth’s neighbouring planets, crashed onto Earth? Well, that won’t be good either. It is worse than an asteroid that can destroy life on Earth.
The Possibility of This Scenario
The possibility of the scenario happening is next to zero. Earth is not the most massive body in the Solar System so it is basically impossible for all the planets to drift in the same direction and crash down on Earth at the same time. Well, if there’s a massive body out there, for example, a large rogue planet, it would have already eaten Earth.
So, what if that happened?
First, as the gas giants are larger than Earth in size, they will push Earth into its system or crash into it. Eventually, Earth will orbit Jupiter or Saturn, as they are relatively close to Earth. Or rather, push it out of orbit and put it into eternal darkness or scorching temperature. And that’s just the beginning or the event that prevents it at last.
If they collided furiously and didn’t have time to do even a thing with Earth, it would swallow Earth instantly. Burning in the giants’ atmosphere, The side that is facing the gas giant would be hotter than lava. Then, in a short time, it would be completely swallowed in the giants’ interior as if nothing happened.
But, don’t call the planet ‘Earth’ at that time. The smaller neighbours, and don’t forget Moon if you want at that scenario, would bump into Earth and will create a planet that glows in visible light. That planet would be an infant super-Earth, which is the most common type of planet. But it is also doomed because the giant planets were coming.
As they drift inward, the Solar System would become a planetary system with 4 hot Jupiters and lots of new asteroids and dwarf planets. But it might be only one, because I mean they would crash together into the ‘former’ Earth.
Planetary Collisions
Although it is almost impossible in our Solar System now, it may be certain in another planetary system. For example, some planetary system’s planets have overlapped orbits. That’s not good for its planetary status unless they are in an orbital resonance.
However, planetary collisions with large ones usually happen when they formed since they would eventually change their orbits if no collisions happened. If multiple planets share their orbits without colliding with each other, they must be in resonance or Langrangian points of each other.
Curious Question 1: What if the whole Asteroid Belt crashed onto Earth?
Like the scenario I’ve talked before, Earth would lose its largest feature in an instant — life. Do you know that theoretical 10-kilometre-wide asteroid that caused the dinosaurs to go extinct? That’s the extinction multiplied by tens of thousands of times, which would end all life on Earth.
Also, scientifically, as they drift to Earth, they won’t 100% crash into it. They would crash into Jupiter and its moons, the Martian system, Earth-Moon system and other celestial bodies. If it randomly went wrong, Earth would most likely only suffer from a tiny fraction of all the asteroids’ impact. The most affected planet is Jupiter. If Earth were one of Jupiter’s moons, we would be in danger if we survived the cold temperature there.
Curious Question 2: What if Moon crashed onto Earth?
If large bodies enter the system, it would suffer from more tidal forces pulling onto each other and break apart more easily, as of other celestial bodies. The limit is called the Roche limit, which you may’ve heard about that in another article.
The same goes for Moon and Earth. Moon will break down when it approached about 18,000 kilometres from Earth, but it isn’t safe either. First, they would form a ring around our planet, which is made up of many small particles gathering in a large system. But, it would eventually rain down on Earth due to its gravity. If the particles are small, it would burn up in our atmosphere and don’t harm Earth. But, if the particles are large, they would impact on Earth, causing destructions.
Still, a world without a moon won’t be that livable. First, ocean tides would become so mild that essential ingredients cannot flow around the ocean and get all eaten up by the oceanic inhabitants. Secondly, Earth’s axial tilt would be unstable that its climate would dramatically change. Thirdly, Earth’s rotational period would speed up, meaning a day would be shorter and the temperature would be cooler.