As of this month we know more about one particularly unusual region on Mars, an area with high elevation called Thaumasia Planum. Researchers in the LSU Planetary Science Laboratory including Don Hood, Department of Geology & Geophysics doctoral candidate and lead author of a new paper in the Journal of Geophysical Research-Planets, have studied the geography and minerology of an area they termed Greater Thaumasia. By analyzing the chemistry of the area, they found that it was most likely created by a series of volcanic events.
We sat down with Don to learn more about why Mars is so interesting but also a relatively new field for geologists.
LSU College of Science: How did you come to study the chemistry of Mars?
Don: I’ve always enjoyed geology, from when I was very young. When I finished my physics degree, I thought, ‘I don’t want to spend the rest of my life researching this. So what could I do?’ I started looking at graduate geology programs. The funny thing is that this program at LSU is the only planetary science program I applied to. The rest were related to rock physics. So this is where I ended up. It’s been really fun.
LSU College of Science: Was studying the geology of Mars vastly different than studying the geology of Earth?
Don: The physics degree actually prepared me nicely for Mars research. The funny thing about Mars is that it’s almost a geologist’s game, but not quite. If you were to attend a geology undergraduate program here at LSU, you would learn all kinds of things that are totally applicable to Mars. But you’d also learn a lot of techniques that we can’t use on Mars yet, because the set of tools that geologists use almost always involve going to the place of study. We can barely do that on Mars. We’ve sent less than ten robots there, that’s it – no people, and certainly not people with drilling rigs or rock cameras.
For Mars, we rely so much on instruments, especially orbital instruments, that it helps to have a good understanding of statistics and the physics of the instruments we are using to observe Mars’ surface. With a physics background, I was well prepared to deal with these techniques, the math behind them and the problem-solving required to use them.
But the study of Mars is certainly advanced enough that geologists can start jumping in. If you go back before the Viking missions in the 1970s, there weren’t any geologists studying Mars, except in abstract. Geologists could hardly touch the study of Mars until the 1970s or 80s. Because no geology instrument had gone there! We just had these really grainy pictures. We had ground observations and telescopes looking at Mars. But Mars is increasingly becoming a geologist’s game. We now have the kind of data from Mars that geologists are interested in. We have chemistry and pictures that are good enough to get topography and layering information from, the kinds of data geologists love.
LSU College of Science: Do you have a favorite feature of Mars?
Don: I geek out over Mars because there are so many things that are mysteries. In any scientific field there are things we haven’t figured out yet. But there are things on Mars that we aren’t even close to figuring out. The perfect example is the Northern Lowlands. The entire Southern Highlands region is a couple of kilometers higher than a third of the planet. We have theories as to why, but we really don’t know why. There are still characteristics of Mars that are bafflingly weird.
I also like that everything on Mars is really big. The combination of lower gravity, and the fact that you don’t get as much erosion on Mars, means that things get really big and they stay really big. That’s a neat feature. Another thing about working on Mars is that everything is very old. If a geologist finds a 3.5 billion years old rock on Earth, that is a big deal. There are only a few samples from Earth that are that old. But one of the first rocks we ever age dated on Mars was 4.2 billion years old. A random rock we picked off the ground, and it was 4.2 billion years old! So everything is really old, which is very cool. Mars also has its own challenges for research.
LSU College of Science: Are there common misconceptions about Mars?
Don: Last year, there was a big discovery related to water on Mars. It was awesome work, and it is an amazing discovery. But the media ran with the finding, and many claimed there was flowing water on Mars. Yes, we’ve made detections that are consistent with flowing water on Mars, but most people picture a trickle of water running down a slope, and that’s more than likely not the case. An idea that came out recently is that the water would be trickling beneath the surface, but it boils off and that boiling causes tiny landslides. So it’s actually a dry process that is also wet to some extent. There are many ways this could happen without having little rivers on Mars. Those might have existed at one point, but not so much today.