What if Earth collided with another planet?

by Carson

Last time, we’ve talked about What If All The Planets Crashed Onto Earth. This time, we’d only focus on one planet. So, what if Earth collided with another planet?

Wait. How is that possible?

These events are called planetary collisions, and they are scarce things that could happen in the Solar System. Those who collided with another planet are usually infant planets within infant systems. When planets are forming, they mostly share orbits, until to a point where they are very stable.

But, these can also occur in something as old as the Solar System through foreign sources, like a rogue planet or an unwelcomed star.

So, what if Earth collided with another planet?

If one day, Venus (for example) crashed into Earth, then the consequences would be severe. First of all, you would see Venus being brighter and brighter, outshining Moon shortly before the collision. Meanwhile, their mutual attraction makes them orbit each other, but let’s suppose something went wrong with the orbit. Then, they came closer and closer, creating megatsunamis with the mighty force.

At the same time, the two planets would accelerate until they crash at 60km/s. If you didn’t book a flight to another planet, you wouldn’t survive the planetary collision. Also, the tidal force would cause unprecedented volcanic eruptions and earthquakes.

If you had not died because of any of those disasters, you wouldn’t stand a chance surviving the following event: The demise of the planet. When Venus entered Earth’s atmosphere, their atmospheres would compress each other. The temperature would be so hot that the side facing another planet would instantly vaporize, and the other side would turn into hot magma.

Finally, when the two collided, lots of friction would act on each other, slowing the rotation down if not stopping them altogether. Trillions of superheated rock would engulf the two planets as they collide, and they would be destroyed without leaving any trace of intelligent life.

The Aftermath (And a Cool Fact!)

You would probably be upset if you survived the demise in a spacecraft or a plane. You would see the planets forming a new asteroid belt, claiming their total write-off. But, some of them could escape the Solar System or get into a higher orbit because of the tremendous amounts of energy. Anyway, don’t expect the Solar System to be the same again after the planetary collision.

In fact, a lot of planetary collisions had happened to Earth in its formation, and one almost killed it. Remember Theia from Moon? Well, it is this Mars-sized object that formed our satellite that makes us more habitable. Also, a planet would have a hard time forming without significant collisions. So, it’s best to have planetary collisions in the planet’s formation phase, but not when it is mature.

Moon, which is formed by a planetary collision between Theia and Earth
To find out this image, download NASA’s Eyes


  1. “NASA’s Eyes”, NASA’s Eyes, https://eyes.nasa.gov/
  2. “What if the Earth Collided With Another Planet”, Youtube, https://www.youtube.com/watch?v=1LdeBY9uNUg

Related Posts

Leave a Comment

* By using this form you agree with the storage and handling of your data by this website.