Posted tagged ‘landing sites’

The 4th MSL Landing Site Workshop

September 24, 2010

Well folks, I’m off to Pasadena to help the Mars community decide where to send its next rover. Long-time readers will recall that i’ve been to a couple of these things before and they’re always fascinating. I was going to post a reminder of what the four finalist sites are, with pros and cons and all that, but it turns out I don’t have to! My friend Lisa Grossman, a former Cornell astronomy major, is now a science writer for Wired! She interviewed me and my adviser earlier this week and put together a nice article summarizing the sites. I’m quoted in it quite a bit, so rather than repeat the same stuff, I’ll just point you over to her piece.

There are a few points of clarification that I should mention. First, the article says that MSL is searching for life, and that’s not really true. MSL is searching for signs of habitability. Obviously finding life would be a pretty good sign! But habitability is broader than just the search for life or even the search for organic molecules. Evidence for habitability could come from the texture of a certain rock telling us that it was deposited in water, or from the detailed chemistry revealing that the minerals in the rock could only form in benign liquid water.

Also, she’s right that some of the clays at Mawrth are kaolinites, which tend to form on earth in tropical soils. But to clarify, I don’t think anyone is saying that the huge amount of kaolinite clays at Mawrth are the result of tropical conditions. They do suggest that there was a lot of water involved though, which is why Mawrth is so interesting.

A final clarification: in the article, it mentions that it will take “several days of hard driving” to get to some of the go-to sites, where the really interesting stuff is outside the ellipse. If it were several days, that would be no big deal. It is going to be more like a year or two. A lot of people are really nervous about landing, only to have to buckle down and drive drive drive to get to the main target of the mission. Of course, all of the sites have good science to do in the landing ellipse, but that is a blessing and a curse for a go-to site. On the one hand, you get some results early on in the mission, but if you don’t have a lot of discipline, you can spend all your time staring at the rocks at your feet and never get to go climb the mountains in the distance.

With that, I’ll let you go read the article. You can also check out my old blog posts about the sites from the last time one of these workshops was held (Gale, Holden, Mawrth and Eberswalde). I’m going to do my best to take notes and blog about the meeting, and Emily Lakdawalla of the Planetary Society will be there for part of the meeting as well. We’ll do our best to keep you informed!

PS – You should totally check out the comments on the Wired article, where someone calls me out for saying that there was water on Mars and says that we Mars scientists are either stupid or have ulterior motives. Someone hasn’t been paying attention to every press release about mars for the past decade or so.

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Mapping Meridiani: Part 1

February 24, 2008

The mantra of Mars exploration is “follow the water,” and my research is no exception. Lately, I have been looking closely at the the Meridiani region on Mars, searching for evidence of water-formed minerals near some of the potential landing sites for the upcoming Mars Science Laboratory (MSL) mission. MSL’s primary goal is to figure out whether Mars is, or ever has been, a habitable planet, so you can bet evidence for liquid water is pretty high on the list of requirements for a landing site.

Meridiani is a particularly interesting region because from orbit we can see that there are huge areas where layered rocks are exposed on the surface. Geologists love layers. To a geologist, layers of rock are like the pages of a history book, filled with information about the distant past. Layers are often associated with water: dust and sand get deposited in lakes and oceans and eventually are buried and become sedimentary rocks.

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This MRO image shows an example of a crater in Meridiani with lots of layers. (Credit: NASA/JPL/U. of Arizona)

There’s more than just pretty layers at Meridiani though. Early on in the Mars Global Surveyor (MGS) mission, the Thermal Emission Spectrometer (TES) found evidence of a hematite in portions of Meridiani. Hematite is an iron oxide (a.k.a. rust) that often forms in water on Earth. The hematite signature was so intriguing, that one of the Mars Exploration Rovers (MER), Opportunity was sent there in 2003. Opportunity has since found loads of evidence for liquid water at Meridiani, including the source of the hematite: small bb-sized spherules of hematite crystals that formed as water seeped through the sedimentary rocks.

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TES map of hematite in Meridiani. The Opportunity landing site is indicated by a black ellipse. (Credit: NASA/JPL/ASU)

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Microscopic image of the hematite “blueberries” as seen by the Opportunity rover. (Credit: NASA/JPL/USGS)

You may wonder, if there is already a rover roving around Meridiani, what’s the point in sending another one? I have a couple of answers for you. The first is that Meridiani is a big place, roughly the size of the Colorado Plateau on Earth. In case you aren’t familiar with it, the Colorado plateau covers about 337,000 kmĀ² of the southwest united states, including a large portion of Colorado, Utah, Arizona, and New Mexico. My point is, Meridiani is a big place. Opportunity has “only” traveled about 11.5 km. To say that we should not return to Meridiani because we already have one rover there is like saying that if you’ve done a day hike in Utah, there’s no point in visiting anywhere in the southwest again.

Another good reason to send a rover back to Meridiani is precisely that we already know a lot about part of the region. By putting together information from two rovers in different parts of the same geologic region, we would be able to get a much better idea of what happened there in the past than would be possible from just one rover.

The best reason to go back to Meridiani, in my opinion, is the evidence that we have for water-formed minerals there. And that’s where my research comes in, but this post is long enough. Stay tuned for part 2.