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using nasa's spitzer space telescope

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we've looked at many nearby stars to

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look for orbiting dust and asteroids and

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comets orbiting debris leftover from the

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process of planet formation we saw

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something very unusual that we hadn't

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seen around any other star we saw

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evidence for a massive collision when

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the two objects collide everything

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happens very quickly in the animation

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things have been slowed down to allow

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you to see the impacting shockwave

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propagate across the surface of this

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devastated planet

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starting from the point of impact and

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circulate into the backside causing

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waves on the surface the entire planet

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becomes molten meanwhile tremendous

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amounts of material are ejected from the

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planet both outside of the system and

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some falls back under the system itself

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depending on the details of the

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collision whether it's a high impact or

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depending on the angle that the objects

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at each other at there there may be a

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growth or there may be grinding away so

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sometimes the planet actually ends up

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smaller after the collision but

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generally the planet grows to larger and

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larger until there's no more material

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left in the system for it to grow from

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while collisions like this are rare we

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don't see this large event in any other

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systems we've looked at with the spitzer

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space telescope collisions like this

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have happened in our own solar system so

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there was a large collision that formed

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our own moon early on as our planets

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formed similarly there are collisions

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like this that stripped the mantle off

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of the planet Mercury and maybe another

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similar large collision Tilted Uranus

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onto its side events like this events

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that we see around this other star and

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events that formed our own moon