Scientist says that during the course of their billions of years, the planets collied with each other in the past. My question is: is there any latest or recent planetary collision in recent times?

  • $\begingroup$ Do you mean anywhere in the galaxy or observable universe or just in our solar system? In our solar system, Rory Alsop's answer is right. The latest (and only) largely agreed upon collision is the Theia impact. It's theoretically possible that one of the gas giants or perhaps Mercury were hit by a planet after that, but we have no way of confirming those hypothetical impacts. $\endgroup$
    – userLTK
    Aug 29, 2019 at 14:38

1 Answer 1


If you are talking specifically about our solar system, then no.

There were many collisions during planetary formation, and there is the fairly well regarded theory that our moon was formed by a collision around 4.5 billion years ago (The Theia Impact, if you want to do more research) but aside from that, collisions aren't really possible any more, except for meteors and other fragments of debris, as the planets are in well settled orbits.

The same goes for moons - anything that wasn't in a stable orbit impacted billions of years ago.

Over the longer term (100's of millions of years) orbits can decay or change, so there will be collisions eventually...

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    $\begingroup$ Technically I think the orbits are chaotic, and we can't rule out collisions in the far future. There are small moons likely to collide relatively soon. For instance Phobos is expected to break up and fall onto Mars within 100 million years. $\endgroup$ Aug 29, 2019 at 14:47
  • $\begingroup$ @SteveLinton - For values of "soon" in the 100 million year range, I agree with you :-) $\endgroup$
    – Rory Alsop
    Aug 29, 2019 at 14:50

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