What would happen to an apple on the surface of the planet Mars?
It’s a striking vision: a bright green or red juicy apple against the barren red rocks of Mars. But an apple on the martian surface would shrivel like a raisin in a matter of minutes. Its juices would boil away into vapor almost immediately. With its liquid gone, the apple would essentially become mummified.
What’s more, Mars is colder than Earth. That dried-out apple on Mars would freeze. Soon, you’d have a freeze-dried mummy of an apple.
But here’s the good news, apple lovers. The apple wouldn’t become rotten. You need bacteria to enable something to rot, and there are no bacteria on Mars.
On the other hand, Mars does have a lot of wind. So the apple might be buried by blowing dust. In that case, the martian soil would corrode the apple – in about a million years.
If the apple didn’t get buried in a martian windstorm, it’d be exposed to intense ultraviolet radiation from the sun. That would turn the apple’s skin black and tarry. But, underneath its blackened skin, the freeze-dried apple would be unchanged.
So you could come back a thousand years later, brush off the dust – or scrape off the tar – and eat the apple. Yummy!
And that’s the fate of an apple left behind by a future astronaut on the surface of the planet Mars.