Antarctic Meteorite NewsletterVolume 32,1

Program News

Curator's Comments
Kevin Righter, NASA-JSC

This newsletter reports 212 new meteorites from the 2006 and 2007 ANSMET seasons from Graves Nunataks (GRA), Larkman Nunatak (LAR), and the Miller Range (MIL). These new samples include 1 diogenite, 3 eucrites,4 howardites, and 6 carbonaceous chondrites (4 CV, 1 CO, and 1 CM).

 

The Meteorite Processing lab and thin section staff has been busy finishing off the characterization of the 2006 season ANSMET samples – all 854 samples have been through the step of initial processing and only a few hundred are left to be formally classified by the staff at the Smithsonian. Additionally, the meteorite collection had 64 requests at the Fall meeting, and had 19 since then, so we have been trying to fill as many of the approved requests as possible, while doing initial processing of the 2006 and 2007 season samples.

 

With the characterization of the 2006-2007 season nearly complete, we can reflect on the bounty of meteorites provided by that team: 2 lunars, 1 martian, 2 paired LL chondritic impact melts, 2 paired ungrouped achondrites (that appear to be associated with brachinites and record early melting events in the solar system), CR, CV, CM, and CK carbonaceous chondrites, 3 irons,
1 ureilite, and 7 HEDs. This great diversity of samples will contribute to many fields of planetary science for years, and is a testament to the value of continuing support of the ANSMET field teams.

New email address for submitting sample requests

In order to better serve the US Antarctic meteorite community, we have a new email address for you to use when submitting sample requests. Please make note of this and use it for sample requests for this newsletter and all future requests:


JSC-ARES-MeteoriteRequest@nasa.gov

 

The new address should ensure that requests will be processed in due time since they can be read by several JSC staff rather than just one person.

 

Hurricane Ike

The greater Houston area was affected deeply by Hurricane Ike in early September. Ike formed September 1 in the Atlantic Ocean, and made landfall September 13 in Galveston, Texas. Despite being a strong Category 2 hurricane, Ike was the third most destructive Atlantic hurricane in history, and had the highest integrated kinetic energy of any hurricane in history, primarily due to its large size. Hurricane Ike made landfall just a few weeks after we released Antarctic Meteorite Newsletter 31, no. 2, in August. Needless to say, the NASA Johnson Space Center and its employees were profoundly affected by this hurricane. The center shut down for close to one week, and then once open, there was a significant recovery period. The Antarctic Meteorite collection faired well during this period, with the short period of power loss to our freezers being offset by the presence of large ice blocks therein. Many samples from our collection were safely stored in the watertight vault in Building 31N. Both Building 31 and 31N, home of all of NASA’s sample collections, had no major damage - lucky indeed considering the damage suffered by some areas nearby. Ike undoubtedly slowed down our operation in the Fall – we appreciate your understanding during the difficult time for us.

Report on the 2008-2009 ANSMET Field Season
Ralph Harvey, ANSMET

Call me Ralfstradamus. In last fall’s newsletter I predicted a challenging season ahead given warnings of aircraft shortages, reduced field party size and a late change to a target icefield littered with shiny dark terrestrial rocks. Obviously the kind of prediction one hopes is wrong, but alas, there was no shortage of difficulties. The story has a happy ending, however, so read on!

 

The field team (Jani Radebaugh, Amy McAdam, Deon van Niekerk, Duck Mittlefehldt, Joe Boyce, John Schutt and myself) made it to McMurdo only one day behind schedule; but even before that delays began piling up. A pre-season reconnaissance flight over the Davis-Ward icefields (between Davis Nunataks and Mt. Ward, and one of the homes of the DOM meteorites) revealed no landing site suitable for the Basler aircraft we were slated to use. That in turn meant two of our people had to go out to the site early, in a smaller Twin Otter airplane, and spend a day or two towing a groomer with a snowmobile to produce a skiway. But then the groomer broke before the job was done; and needing another Twin Otter flight to deliver a replacement, the delays piled up. It wasn’t until Dec. 23 that the field team was finally complete, two weeks of our six-week field season gone. We’ve had delays approaching this duration in the past, but this one had a personal impact on me- I had planned to come OUT of the field on Dec. 22, so in the end I missed the fieldwork entirely, letting my mid-season replacement Joe go out in my stead.


Image of Nostradamus
 

Of course, every gray cloud has a silver lining. Many Antarctic projects had no field time at all; we at least got 2/3rds of what we’d planned. My children were very happy to have daddy home for only my 2nd Christmas in their lifetimes, and most of the field team appreciated the shorter deprecations of the 4-week season (except for Duck and John, who endured a full 6 weeks). High winds during the shortened season meant only 16 days of searching, yet Davis-Ward revealed a startling number of finds and very high density concentration. Before the season, John and I felt that good weather might allow us complete recoveries at the site. Now, not so much - in fact, we’ll be lucky to finish it with two more full-size seasons. The best analogy to the Davis-Ward icefield among previously-known sites is the Lewis Cliff Ice Tongue, where a high density of finds led to 3+ full seasons of work and many great specimens, acquired only through slow, highly methodical searching in the accompanying high density of terrestrial rocks. The season total was 521 finds; there are some nice achondrites and carbonaceous in that collection and certainly other interesting samples masquerading as modest-sized ordinary chondrites. Let me close with a final cryptic quatrain from Ralfstradamus (interpret as you will).

View of part of the icefield searched from the flank of Mount Ward

View of part of the icefield searched from the flank of Mount Ward

Quote from Ralph Harvey
 
   

Behind the Scenes
Tim McCoy, Smithsonian Institution

 
   

If you are a regular reader of this Newsletter, you are probably familiar with the workings of the Antarctic Meteorite Program. You may keep tabs on those that join Ralph Harvey in the field each year, you read Kevin Righter’s article in the Newsletter, and you know the staff at the Smithsonian who classify the meteorites. Unless you have worked with one of those organizations, you are probably far less familiar with the hundreds of people who have to do their jobs to make it possible for us to announce new meteorites to the community. Staff at the National Science Foundation have to process the grant; maintenance personnel in McMurdo have to ensure safe operations of the aircraft in the field; liquid nitrogen has to be delivered at Johnson Space Center for curation; and, of special note for this newsletter, technicians at JSC and the Smithsonian have to prepare the thin sections we need to complete the classifications. You may have noticed the last couple of newsletters were a bit on the thin side. A big reason for this has been turnover in the thin section labs at both JSC and the Smithsonian. For the latter, our long-term thin section preparator Tim Gooding moved on to a position at the National Institute of Standards and Technology. We wish him well in his new job. While we’ve been searching for his replacement, thin section preparation has been a bit slow. We hope to have a new hire in place by the next newsletter and you should see an increase in the number of “interesting” meteorites we describe. But remember, it’s not just the field party members or curators who make this newsletter possible – it really takes a large, talented, dedicated team!

The team arrives at Pegasus Field, Antarctica
The team arrives at Pegasus Field, Antarctica
The team collecting a “very small” meteorite
The team collecting a “very small” meteorite