Ice Diary 9: Climbing the Mountains of Mars
Ice Diary 9
Climbing the Mountains of Mars
1 January, 2003
Boy have we been working hard lately! We are nearing the 400-meteorite mark and are hoping to break the 500-meteorite mark before we leave. The weather hasn’t been cooperating, though. Yesterday started out calm and relatively warm. By the time we started our searching, the wind had picked up to at least 15 knots and the temperature was right at 0F. We recovered 17 meteorites before we called it a day.
|Linda, Carl, Dante, Andy, and the rest of the ANSMET team want to wish everyone a Happy New Year
Credit: Danny Glavin, TEA
These were some of the most beautiful meteorites I’ve seen this whole trip. Two of them appear to be achondrites. Meteorites basically fall into two groups: chondrites and achondrites. Chondritic meteorites come from small asteroids that never formed a core, mantle, and crust at the origin of the solar system. They are composed of chondrules: small round, spherical concretions that probably represent droplets of material from the protoplanetary disk that existed 4.6 billion years ago. Achondrites don’t have chondrules and come from larger bodies that do have a core, mantle, and crust. What’s more exciting is that martian and lunar meteorites fall into the classification of achondrites. Saying that we found a couple of achondrites doesn’t necessarily mean we found meteorites from Mars or the Moon, but it is a possibility.
The ANSMET P.I., Dr. Ralph Harvey, pointed out to me that NASA is very interested in finding more Martian meteorites because they provide the most information on Mars without actually going there. Ralph also enjoys involving NASA with ANSMET because, at heart, he is interested in the exploration of space.
According to Ralph, "In some ways, it’s very much like a science fiction story, where astronauts come to Antarctica to train for a mission to Mars." Dean is keeping a journal of the dynamics of a small field team working under these conditions in order to help NASA prepare astronauts for a Mars mission.
Dr. Cady Coleman is the second astronaut to join an ANSMET team, and will probably not be the last. Ralph commented that astronauts are physically fit, adventurous, and are able to complete a job under demanding conditions. That makes them ideal ANSMET members.
2 January, 2003
There have been a few requests for the female perspective, so greetings from the females of the Beardmore ANSMET team!
Living in the extreme environment of Antarctica is the same for us as with the rest of the team. Everyone pulls some weight – literally – from lashing sleds, lifting boxes, putting up our own tent, fixing snowmobiles, and much more. Do we work hard? Yes! Are we tired at the end of the day? Absolutely. But so are the guys. Being here is hard physical work, and even just dealing with the cold will tire you out.
So with all the similarities between us and the guys, what are the differences? Our tent, for one. The tent is more than just the place where we keep warm; it is our home away from home. It is filled with reminders of our family, friends and home. Linda brought a huge wad of photos that she changes out every few days. We have holiday decorations — Nancy’s Mom sent her some great Christmas socks and hair ornaments.
Daily chores keep us healthy and warm. As soon as we get out of the field, we fill stoves and chip ice. Nancy and I take turns without ever really keeping track. We don’t spend a lot of time deciding what we want to eat each night, nor do we follow any type of schedule. All of it gets done sometime before bed, which happens to be the latest in our neighborhood, generally close to midnight. It’s hard to believe, but Nancy has a fair number of scientific responsibilities that can take upwards of two hours — downloading the GPS data for the day is the main one.
We usually end the evening by filling our stoves and water bottles for the next day. A little reading until the tent gets too cold, and then we cocoon under the sleeping bags. We also get up the latest, about 7:30. Neither of us are big breakfast eaters. Speaking of food, we would like to point out that we eat pretty differently out here than at home. Lots of meat and butter and fat go into our meals, while those foods that can’t be frozen (soda, pizza, sour cream, lettuce, fruits) are not available. Amazingly, we crave all that fat in order to keep up our energy (gotta lug almost 10 extra pounds of bunny boots all day) and stay warm. Linda is not a big chocolate eater, but she has found herself eating a bar a day — and has still lost a few pounds!
Other differences between life in a tent versus life back home are related to indoor plumbing and access to large quantities of hot water. We get pretty dirty out here after weeks of no showers, and we are willing to accept that, especially since everyone else is in the same boat. We leave all the usual toiletries behind. We care very little about how we look, although we keep an eye out for frost nip and other cold weather conditions that might appear on exposed skin. Keeping warm is more important, although Linda hates how much like a blimp she looks in all that gear. Linda doesn’t even look in the mirror unless Nancy is laughing at her hat hair. Of course, we are looking forward to tomorrow evening, which will be our second "bath" night in the field. Linda has even gone so far as to run around outside without a hat just so everyone will see her clean hair, if only for that day. We also suspect that we use many, many more baby wipes than the men do.
So how do the guys treat us? Just like anyone else, which is great, ideal, perfect. We’re a good, hard-working team. It is worth noting that the other ANSMET team in the field right now, the reconnaissance team, has equal numbers of men and women (2 of each). Last year at one point in the ANSMET season, there were 5 women and 3 men in camp. There have been a lot of women involved with ANSMET teams over the years.
3 January, 2003
After a short weather delay, we headed back to That" Moraine this morning for a systematic foot search. I don’t think any rock was left unturned, nor was any wind scoop unexplored. At the end of this methodical search, we found 14 meteorites.
We decided to use the afternoon for a reconnaissance trip. We traveled 20 minutes north of camp to a blue ice field only visited once before by Jamie and Danny. Fuel was stored there from the Beardmore Camp, so Jamie and Danny brought some of it back to our MacAlpine Camp. Danny said the ice was "like a frozen tsunami," and I think he was exactly right. A large wind scoop is formed where the ice meets the mountain, causing the blue ice to plunge toward the barren rock.
We hiked up a small peak to get an idea of the extent of the blue ice and how we should go about searching it. Once again, it was strange to set foot on dry, snow- and ice-free ground. This rock was formed from iron-rich volcanic rocks and had a slightly rusty appearance. I felt as if I was climbing a mountain on Mars, and one of the reasons I wanted to come to Antarctica is that it is the closest terrestrial analog to Mars.
|The Beardmore team doing some high altitude reconnaissance. Pictured left to right: Carlton Allen, Andy Caldwell, Scott Messenger, Jamie Pierce, Linda Welzenbach, Daniel Glavin, Dante Lauretta. Nancy Chabot not pictured because she was following her wanderlust and found an irresistible path down the mountain.
On the way back down, Jamie found a meteorite on dry soil, and another was found on the blue ice. We spent a lot of time on that ice, but mostly saw small windblown rocks until Dante found the largest meteorite of the day. It makes me wonder when we find one lone meteorite in a field of blue ice – was it brought there by the flow of the ice, or did it come from a recent fall?
I find it remarkable that these rocks from space even make it to Earth. It’s generally accepted that most meteorites come from asteroids. They are produced when asteroids collide, and their debris falls into an orbit that intersects the Earth’s orbit. They enter our atmosphere travelling at speeds anywhere from 17,000 to 40,000 miles per hour. As they pass through the upper atmosphere, friction with air particles causes the outside of the meteorite to attain temperatures and a luminosity comparable to the surface of the sun!
However, rocks are poor conductors of heat, so the inside of the meteorite stays very cold. The meteorites we find have a thin black crust that looks completely different from the interior of the rock. (Meteorites don’t weather much in Antarctica, so they retain their black fusion crust long after they fall.) Some meteorites melt partially and take on a shape not unlike the bottom of the space capsules used early in the space program. These meteorites are described as "oriented."
In addition to these high temperature contrasts, the meteorite is also slowing down at an extreme rate. This causes it to experience G-forces that are completely outside of the experience of most people. In my classroom, I usually find a student who weighs about a 100 pounds. I explain that just sitting in her desk, she’s experiencing 1G of force. If she were in a car going around a corner quickly or braking quickly, she could experience 2Gs, and therefore, for a moment, weigh 200 pounds. On a roller coaster, she can achieve 4Gs, so she weighs 400 pounds. But if she were a meteorite, she could experience as many as 300Gs when entering the atmosphere. For the few seconds she’s plummeting to Earth, she weighs 30,000 pounds!
Meteorites are just rocks, and most of them (especially the stony ones) cannot take this force and break up anywhere between 10 and 20 miles above the surface. Fragments of the meteorite rain down over a large area called a strewn field." In most cases, the meteorites soft" land without making a crater. People who have recovered meteorites after witnessing them fall often describe them as cold to the touch. Although legend and folklore say they start fires and are radioactive, the only dangerous ones I know of come from Krypton and are harmful only to Superman.
We often find several meteorites together that look like they could have come from the same fall. The glaciers do a good job of mixing them up, so it’s hard to tell just by looking at them. They can be analyzed later by extremely precise instruments that can identify trace elements and compounds. This can tell us about the chemistry of the early solar system, so we are careful when collecting the meteorite. We would hate to see a new class of meteorite identified because my candy bar scraped across it. I can see the headlines now, "New meteorite: part rock, part iron, part nougat."
Since 1976, the Antarctic Search for Meteorites program (ANSMET), funded by the Office of Polar Programs of the National Science Foundation, has recovered more than 10,000 specimens from meteorite stranding surfaces along the Transantarctic Mountains. Dr. Ralph Harvey and John Schutt are members of each field party, serving as ANSMET continues to be one of the few Antarctic research projects that invites graduate students and senior researchers from other institutions to participate in our field work on a volunteer basis–including the Teacher Experiencing Antarctica (TEA) program. As a multi-agency collaboration, the NSF supports field operations, NASA supports storage curation, distribution and notification of recovered samples, and the Smithsonian provides long term curation facilities for the collection and assist in sample characterization.
In this multi-part Ice Diary series, all commentary is attributed to Andy Caldwell unless otherwise noted, and reprinted by permission as part of his participation in the TEA program.
Related Web Pages
Ice Diary I: Shooting Stars on Ice
Ice Diary 2: Great Scott, A Ghost
Ice Diary 3: Cheer for Team Meteorite
Ice Diary 4: The Hunt Begins
Ice Diary 5: MacAlpine Hills or Bust
Ice Diary 6: Contacting The Mother Pod
Ice Diary 7: Summer Christmas
Ice Diary 8: Where No One Has Gone Before
Ice Diary 9: Climbing the Mountains of Mars
Antarctic Search for Meteorites (ANSMET)
Planetary Materials Curation (NASA/JSC)
Mars Meteorite Compendium (NASA/JSC)
AMLAMP: Antarctic Meteorite Location and Mapping Program (database of where meteorites have been found)
National Science Foundation (NSF) Office of Polar Programs
McMurdo Long Term Ecological Research (LTER) project
Ice Cube of Exotic Microbes
Antarctic Microbes Colonize under Mars-like Conditions
Meteorite Repository (JSC) Rock Descriptions
NIPR Meteorite Collection (Japan)