Note: I am posting my old blog entries from elsewhere on the internet. This entry was originally posted on 8/05/08.
Some of you may have seen some reports online that there’s some sort of secret result from the Wet Chemistry Lab portion of the MECA instrument, the instrument suite that also includes the TECP (the instrument I work on), and that someone has been briefing the White House about life on Mars. Exciting as this sounds, it isn’t true. There’s a lovely writeup of the whole situation over at the Planetary Blog, and I don’t think I can improve on it, so I’m just going to ask you all to read it. None of the instruments on Phoenix can actually detect life; one of our goals is to figure out if this location could have supported life, which is a different (and easier) measurement. Here’s a NASA press release on the whole thing and we had a press teleconference you can listen to here. I wonder if the rumors got started by the fact that there was a big press conference for TEGA and the meteorology team last week, and one of the reporters wanted to know why MECA wasn’t at the press conference. (The answer to that is: we are still working on understanding what our data means!)
You can read about that other press conference here but our big news is that we finally got our second sample (from scrapings of soil from one of the trenches) into TEGA, and have directly measured water ice. The sample was named “Wicked Witch” and you can see in the photo I posted a few days ago that Dr. Bill Boynton, science lead for TEGA, dressed appropriately for the press conference.
I got asked by a friend what this result really means. I know that the press releases that come out of NASA makes it sound like we re-discover water every few months. We’ve detected water elsewhere on Mars – for example, we’ve known for years that the bright deposits at the north and south poles are water ice based on spectral and radar measurements. From the shape of canyons elsewhere on Mars, we think water probably flowed across the surface billions of years ago. Spirit and Opportunity have seen geological landforms and geochemical evidence for surface water at their respective locations, even though there isn’t any there now.
What’s cool about the TEGA measurement is that we’ve touched the water, and measured it directly (rather than indirectly from orbit). It is more a confirmation that we have water rather than a new discovery. This is an important aspect of science – we have several different lines of evidence (TEGA, the sublimating white particles we saw earlier, the results from the neutron spectrometer on Mars Odyssey) that all point to the existence of water here. This was a major goal of the mission, but it is only the first step.
We want to understand the history of the water here – water would not be deposited in this location under current climate conditions. The chemistry of the water ice and the soil can tell us if there was once liquid water here, and if the conditions here are hostile to life. You can read more about this on the Phoenix website about the history of water on Mars and about how our specific measurements relate to our goals and objectives.
It is also possible that sometime in the future, human explorers could dig down to water ice and use it, but that’s not a major focus for us. We’re a science-driven mission rather than a human precursor mission, but those people working on developing human exploration of Mars will no doubt take our results into account in their plans.
Here’s some other cool stuff recently released by the team: A movie of nighttime LIDAR observations. The LIDAR is a laser beam that shoots up from the deck and bounces off of clouds passing overhead, which allows the meteorology team measure how high up the clouds are. The view is looking almost straight up and includes about 1.5 km of the beam. The moving material in the background is dust in the atmosphere.
Also from the meteorology team, a movie of telltale wind direction and speed observations. The telltale is basically a bob hanging off a wire that sits at the top of the met mast, and we take pictures of it moving in the wind. There’s a mirror set up so that in one image we can see both the side view of the telltale and the top-down view of the telltale (the little x at the bottom) so we can tell which way the wind is blowing.
Here’s a cool movie showing how a sample gets into TEGA.
We’ve got a full color panorama now, and here’s a movie zooming in on some of the features.
Some of you might be interested in how we take color images – we actually take a series of black-and-white images through different colored filters, and then use those to assemble a color image. There’s a little video about that here.
Here’s a video that shows a zoom in to the landing site. The atmospheric science group is using this to help think about their wind observations because they want to understand what effects the local topography is having on the weather conditions at the landing site. I’m mostly including this one because it builds upon a graphic I put together for them – the atmospheric folks were sitting around wishing they had some topography data, and I happened to be the geomorphologist in the room with them who knew how to get them some data. This is a lot fancier than what I gave them, and doesn’t have the graphs that I made, but they left some of my labels on at the end. The team thinks that the fact that the wind comes from the east at night might be due to cold, dense air coming over the valley wall to the east of the landing site. FInally, here’s a short clip from NOVA ScienceNOW. It’s mostly about the Wet Chemistry Lab. It’s a great description of the instrument and the excitement of seeing the first data come down, and you will see a lot of my fellow MECAns, as we call ourselves.
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