Re: If you sent something with iron on it to Mars, would it rust?

Lindsey,

Great question.... difficult one too. Planetary scientists are still trying to answer these questions. As for the iron, it occurs in very small grains. The oxidation of it most likely was caused by water, although there is some experimental evidence that ultra-violet radiation from the sun may have caused a little of the rust, but not very much. As to whether there were/are large amounts of iron on the surface, it depends on your reference. Mars does have a lot of iron, but at the surface, it is not likely in many (or possibly any) deposits like we mine on earth. The large amounts of dust have been spread across the planet covering much of the bedrock, so everywhere we look, we see sand and dust with its oxidized iron. Now for the water, this is a really interesting question to me personally and many others. It seems readily apparent that Mars once had an abundance of water and that it flowed on the surface. We multitudes of examples of large channels and valley networks that strongly suggest a water origin for them. Whether rain is necessary is actually a much debated subject, and no consensus has yet been reached. It seems at the very least that groundwater may have played a significant role, and rain may or may not be necessary to feed these systems.

If you actually sent iron TO Mars it might rust, because there is water in the atmosphere, but it would probably take a while. It would be covered with iron-bearing dust and sand much more quickly.

Great Mars information from JPL

Good luck -- Steve