Astronomy Colloquium for 2018-02-07

Series: Astronomy Colloquium
Date: Wednesday 07-Feb-2018
Time: 16:05-17:00 (4:05-5:00 pm)
Location: ATL 2400
Speaker: Dr. Don Brownlee (University of Washington)
Title: What comet samples tell us about the origin of the solar system

The analysis of collected comet samples has provided direct information on the detailed nature of rocky grains that existed in cold regions of the early solar system. The typical rocky solids in the 2-50 Ám size range are anhydrous materials that formed in the solar system at incandescent temperatures. It is clear that ices, organics and presolar interstellar grains could not have survived these high temperature environments. Many of the comet solids are complex assemblages that are directly comparable, in detail, with high temperature materials found in primitive meteorites. It appears that most comet grains >2Ám formed in the inner solar system and were transported to distant cold regions where ices could form. The rocky components of comets are a broader mix of materials than are found in specific meteorite classes; evidence that comets contain materials from a broad range of nebular environments. It seems likely that most outer solar system bodies received similar mixes of rocky inner solar system grains. The sample-based view of comet solids is quite different from many expectations.

Colloquia are usually preceded by espresso and ice cream at 1:45 pm outside room PSC 1150 and are followed by an informal reception at 5:15 pm in that room. Anyone interested in talking with the speaker, or being added to the colloquium announcement email list, should contact the colloquium organizer. Lunch will normally be reserved for the speaker to talk to graduate students.

Colloquium Organizer: Prof. L. Drake Deming


Special accommodations for individuals with disabilities can be made by calling (301) 405-3001. It would be appreciated if we are notified at least one week in advance.


Directions and information about parking can be found here.

This page was automatically generated on: 24-Jan-2018.