This past winter (2011-2012) I was lucky enough to join the Antarctic Search for Meteorites (ANSMET) team to hunt for meteorites in Antarctica. The ANSMET programme, funded by NASA and the US National Science Foundation and run between Case Western Reserve University, NASA JSC and the Smithsonian, has been running since 1976 exploring the ice of Antarctica for meteorites. So far about 20,000 meteorites have been collected and made available to the scientific community to study to understand planetary processes. Most of these meteorites originate from the asteroid belt, but some very rare ones have come from Mars and the Moon!
Left: Lower left shows a map of Antarctica, where the highlighted area is blown up in a big map showing Transantarctic Mountain range and the ice fields where meteorites have been found. Right: Sketch showing how meteorites falling on the ice get transported and concentrated next to mountain ranges. Images: NASA.
Why Antarctica? The team collect meteorites in Antarctica because they are well preserved in the cold dry icy environment. They are also easy to spot as dark rocks on the white ice. Most meteorites are found in icefields close to the Transantarctic Mountain range – you can see a map where all the yellow labels mark places that meteorites have been collected. These localities are really great for concentrating lots meteorites that have travelled from the South Pole ice plateau, and are brought up to the ice sheet surface near mountain ranges
How do we get to Antarctica and what is life like on the ice? Our team of six guys and two girls flew to Christchurch, New Zealand, and then were flown down to the US McMurdo base in Antarctica. We spent a week or so in McMurdo preparing for our expedition. We packed up our gear and selected food supplies to last us for six weeks camping on the ice. When we were trained and prepared we flew out to the Transantarctic Mountains on a military Hercules plane with skis and then a smaller Twin Otter plane. We set up camp in the Miller Range – a stunning area with mountains and glaciers. Our camp consisted of four tents, where we lived two people to a tent, and a tent with a toilet (a glamorous bucket!) and one that we used to all gather in the evenings (the party tent). Temperatures varied from about -10°C down to -30°C outside, but when the wind was blowing from the South Pole plateau, it felt a lot colder! You have to wrap up in many layers to stay warm – I typically wore four layers on my legs and between five and seven on top, including my big orange down jacket. I also wore a full face mask to protect my face and eyes from the cold and glare from the sun.
Arriving and life on the ice: Images: Antarctic Search for Meteorites Program / Katie Joy.
How does meteorite hunting work? We had a surprisingly large amount of snow during our field season – which is rather unusual for Antarctica as it is supposed to be a cold dry desert. The snow caused us lots of problems trying to find the meteorites, so we spent a lot of time stuck in our tents rather than looking for meteorites. When the weather was good enough to allow us to look we would get on our snowmobiles (skidoos) and drive out to a new area of ice. We lined up and drove up and down in straight line formation with about ten metres between each team member. When someone spotted a black rock on the ice they would jump off their skidoo, check it was a meteorite, and then wave their arms madly in the air to call the other people over to come and help collect it. We photographed the meteorite, logged its location and carefully put it into a special collection bag ready to send back to NASA. Sometimes we would walk across the ice to search, and other times we would look in rocky areas called moraines to see if we could spot a meteorite. It was a frustrating process when you didn’t find a meteorite, but great fun and satisfying when you did. Our team found 302 stones this year, which considering the bad weather, wasn’t a bad total at all. In fact we were lucky enough to collect the 20,000th sample ANSMET have collected, which was cause for a big celebration. The samples are all now back at NASA Johnson Space Center ready to be classified and studied by scientists all over the world.
Collecting meteorites on the ice (the meteorite are the brown/black rocks we are all gathered around!): Images: Antarctic Search for Meteorites Program / Katie Joy.
Would I do it again, live for six weeks on the ice, not be able to have a shower or wash my clothes, go to the loo in a bucket and have no internet and limited contact with the outside world… yes… in a heartbeat! Antarctica and Miller Range are absolutely beautiful, and it was brilliant being part of a really great team of people finding samples of other worlds that will help us better understand the history of our Solar System.
More information about the ANSMET programme can be found at http://curator.jsc.nasa.gov/antmet/program.cfm and http://geology.cwru.edu/~ansmet/ and if you are interested in looking back at the ANSMET 2011-2012 season blog it can be found at http://humanedgetech.com/expedition/ansmet2012/
Thanks to Ralph, Jim, John, Anne, Christian, Jesper, Jake and Tim, and all the staff at McMurdo for a great field season.
Please note that all images in this blog are not to be redistributed (thank you!).