AS A LITTLE GIRL, Nina Lanza always wanted to work on a spaceship. OK, plenty of kids might have had similar aspirations, but she actually did it.
Today, Dr. Lanza heads the Space and Planetary Exploration in Space and Remote Sensing at Los Alamos National Laboratory. She is a principal investigator of the two rovers we have on Mars: the Mars Curiosity rover and the Mars 2020 Perseverance rover.
Currently, she studies the possibilities of life on Mars – past and present –encouraged by the surprising discovery of manganese minerals.
So how does one get to work on a Mars rover?
Well, since I was little, I wanted to work on a spaceship. Of course, I didn’t quite know how to do that. I thought it made sense to study astronomy; I thought that’s how you studied space. So I did my undergraduate study in astronomy. Then I realized – right at the end – that if you want to work on space missions to other planets, you really need to know about rocks. So I had the wrong major.
So I applied to geology master’s degree programs, and that’s when I realized that to actually get involved in one of these missions, you need to work with somebody who is on the mission. So after my master’s, for my PhD, I headed to New Mexico to study with Dr. Horton Newsom at UNM.
One day, he walks in and says, Hey, I’m a coinvestigator on this instrument that’s going up on the next Mars rover. You wanna join that team? Uh, yes, yes, yes, yes….
So we began work on the ChemCam instrument that is currently on the Curiosity rover.
What is ChemCam?
So there are two rovers: Curiosity and Perseverance. They are pretty much twins – fraternal, not identical. But they both have a box on top of their heads. ChemCam is the box on Curiosity. It’s short for chemistry in camera, so it’s a chemistry instrument, and it also takes pictures.
ChemCam has an infrared laser that we can focus on a target up to about seven meters away. The laser heats up the target so that it vaporizes. We’re using a rock-vaporizing laser to make plasma, increasing the atoms to a higher electronic state; as they come down from those excited states, they emit characteristic photons. Basically, you can look at the color of light that your laser has made on the rock, and you can figure out what elements are in that rock. You don’t have to touch the sample to be able to see what elements are in it. We’ve done almost a million of these in the ten years we’ve been on Mars.
Perseverance has a slightly different box called SuperCam. It allows us to record audio from Mars. Sounds are a bit different on Mars than they are on Earth. What we think of as sound is actually vibration, right? Mars’s carbon dioxide atmosphere is much less dense, which means you don’t hear a lot of the higher-frequency vibrations. It’s an overall lower-frequency sound.
You are particularly interested in the manganese in these rocks. Why?
Manganese is a really cool element that has some close ties to life on earth.
Two things are needed to form manganese minerals: a lot of liquid water and strongly oxidizing conditions.
To put this into context on Earth, we have had a lot of water from the start, but Earth was not an oxidizing place until we put oxygen in the atmosphere. And that came from life. So there was a big change in our environment when cyanobacteria figured out how to make oxygen. That really changed the geology of the Earth.
That’s an indirect connection to life. People have long wondered if we should expect to see these types of materials on Mars, and it turns out that we’ve found manganese on Mars. But how? It’s not an oxidizing enough place to make these materials. Even in the past, there shouldn’t have been oxidization in a place where there was no oxygen in the atmosphere. Or was there?
It’s very hard to explain where these manganese minerals came from on Mars. Does that mean it was life? No, but it does mean that it’s really important for Perseverance to grab some manganese and bring it back. We’ll have actual samples in our hands in 2033. That sounds far off, but it’s close, actually.
It’s really exciting to be able to work on these types of missions because every day we see something new, every day we learn something new, and Mars is always surprising us.
Like what?
We found with Curiosity – and are confirming with Perseverance – that Mars was truly a habitable place, a place where life as we currently understand it could exist. At least it was three and a half billion years ago. We’ve had a sense that there was water there, and we’ve found old locations that, if they were on Earth, would have been teeming with life.
Life on Earth had already arisen by the time these habitable environments on Mars existed, so it’s not a crazy thought that there could have been life there. Before the rovers, I don’t think we appreciated how habitable Mars used to be. I mean, it’s not very habitable now! Not really a great place to live. That being said, there are plenty of microbes on Earth that would happily live on Mars as it is today.
So even though Mars is not habitable like it might have been in the past, it’s still not actually impossible for life as we understand it to subsist in the sub-surface. It opens up some really cool possibilities. So that’s surprising, right?
So there could have been martians.
There could have been martians. We don’t know if there were martians, we don’t know if there are martians, but these are no longer crazy questions.
At the same time, people get carried away. According to the internet, we’ve seen a human face, a monster crab, and a cannonball on Mars.
It’s easy for people to look at images from Mars and see all sorts of things that look like alien life. The human face is actually a mesa, the crab is simply a rock, and the cannonball is just a pebble. After all, humans evolved to find recognizable patterns amid chaos. There’s even a word for it: pareidolia.
But what’s really interesting is how Mars is helping us understand life on Earth. Because how life began here is still very much unknown. Earth’s rocks are much younger since they’ve been recycled more. But Mars’s rocks are like a museum; they are in ancient, pristine, habitable environments similar to what once existed on Earth. But on Earth, we don’t have those rocks anymore.
Sometimes people are like, Why do we study Mars? It doesn’t matter, it has no effect on us. But it does!
Because we’re trying to understand the origins of life, and we don’t really know anything about our origin on Earth. On Mars, we can test hypotheses about how life could arise, how all of it began.
Learn more at ninalanza.com
Photo Mary Moon
