The simple answer is likely "yes," but the most accurate answer is "no one knows." The red hue of Mars comes from a fine layer of iron oxide that has gone through a transformation similar to rust, but in the absence of oxygen and water.
What exactly that means is a matter of heated debate. We need to find the answer quickly, however, because there are at least 14 independent missions to Mars in development right now, and the closest repair shop will be 34 million miles away.
Before we send civilians into harm's way, corrosion experts and structural engineers are working overtime to understand how rust, or the equivalent of rust, is going to affect the spacecraft and instruments that we send with these brave new explorers. Here’s a round up of common questions and answers that we've learned so far about exoplanetary corrosion:
"I thought rust required oxygen and moisture."
It does, and the laws of physics and chemistry work the same on Mars as they do here. Some scientists claim that all the iron oxide proves that Mars once had plenty of water. In fact, the atmosphere retains a tiny amount of water vapor, 0.03 percent, and a trace amount of oxygen at 0.13 percent.
However, the Martian atmosphere is composed almost entirely of carbon dioxide (more than 95 percent) and the rest is a mix of nitrogen and argon. Obviously, those trace amounts of oxygen and water vapor cannot account for the rust-like transformation covering the entire planet. It may be something else entirely.
"Without water, this rust-like transformation is over now, right?"
Probably not. There’s a new but unpopular theory based on what we have learned so far from the Pathfinder mission. There is a great deal more iron on the surface than there is in the rocks of Mars, so it may have come from meteorites instead of ancient volcanoes.
If so, then the carbon dioxide and other gases in the atmosphere, charged by unshielded ultraviolet light from the sun, could generate negative ions of oxygen (superoxides) in iron dust, even without any exposure to water. That would mean that the people we send to Mars would have to learn how protect their equipment from an entirely new variety of corrosion.
"But we’re a long way from sending people to Mars, aren't we?"
Not exactly. Inspiration Mars is funding a round trip for two, which may launch as early as 2018. Mars One intends to begin an entire colony on the surface by 2023. Both are less than a decade away, and the margin for error will be negligible.
In case there was any doubt about the popularity of this one-way mission, 200,000 video applications for Mars colonists have already been accepted. NASA is planning four unmanned missions and eight more projects are in the works by other nations and private contractors.
"Who's working on this problem?"
Dust engineers are leading the charge to fight Martian corrosion. Martian dust will be toxic and potentially disastrous in its corrosive qualities. The Curiosity rover found something similar to gypsum that is more dangerous than coal dust and deadly for fine electronics. Grant Anderson of Paragon Space Development explained:
"What you're going to want to do is pump out the CO2 and then let in air. That creates eddy currents, which creates flow. You've got such fine dust on Mars that you won’t be able to keep it down, and the person will be breathing it in."
Also, as astronauts found with moon dust, Martian dust will have a high static charge due to the low gravity and thin atmosphere Mars maintains, so it will fly everywhere and stick to everything. In the end, rust may be the least of our problems.