Tagish Lake

We’ve added a zoomable backscattered electron mosaic of Tagish Lake (unstitched, I’ll do that later). It is interesting to compare Tagish Lake to say, Murchison. TL is very fine-grained. Or maybe less compacted is a better way to describe it (thanks Lionel!).


Asteroid 4 Vesta (right) and a colorized backscattered electron image of the Kapoeta meteorite (left), a howardite thought to originate from Vesta’s surface. The difference in scale between these two images is 100 million.

Schultz & Franke Noble Gas Database

We’ve added a computer-readable version of the (extremely valuable!) Shultz & Franke (2004) noble gas database for meteorites to the Resources page. There are three separate Excel files for stony, iron, and stony-iron meteorites. Thanks to Lionel for his work on this!

CO Ice in Interstellar Comet 2I/Borisov

This interstellar visitor appears to be enriched in super-volatile CO ice, published in Nature Astronomy. It is completely astonishing that this measurement has been made on an object from another planetary system! I love it, this is a great time to be a cosmochemist.

It makes sense to me that this comet may have sampled the very cold, outer regions of its own system, where it was also more vulnerable to ejection by a passing nearby star.

My dream is to identify one of these interstellar comets producing a lot of dust that intersects with Earth’s orbit, then do a targeted IDP dust collection with high-altitude aircraft, where IDP stands for interstellar dust particle, instead of interplanetary dust particle.

Kevin McKeegan talk at Wash U

Professor McKeegan of UCLA, a graduate of the physics department and the Laboratory for Space Sciences, will be giving the McDonnell Distinguished Lecture next month at Wash U. McKeegan and his research group have done a lot of really fantastic work. In my opinion, McKeegan and team’s measurement of the oxygen isotopic composition of the Sun was the single most important measured ever made in cosmochemistry, and indeed one of the key findings in all of planetary science. This measurement has motivated a lot of the work our group is doing right now. We’re very excited to have him back in St. Louis!

NASA grant for Nan to study presolar grains

Nan Liu, research assistant professor in physics in Arts & Sciences, received a $493,885 grant from NASA to study presolar grains in primitive meteorites. Under her new project, “Isotopic Characterization of Presolar Supernova Grains: Constraints on Dust Formation and Nucleosynthesis in Type II Supernovae,” Liu will obtain isotopic and structural compositions of presolar grains from ancient supernovae to constrain the production of elements and dust condensation. Her goal is to improve the understanding of the origins of the solar system.

BSE Color Mapping & Contrast Stretch

I’m experimenting with contrast stretching for BSE images. I think it might be useful to bring detail out of the 16-bit images, though it makes it more confusing to identify phases based on Z contrast (as linearity was compromised to bin the output 8-bit data into 256 percentile bins). I think a stretched and color-mapped BSE image would be useful in combination with X-ray overlays (which I have a student working on now).