Bibliographic Details
| Title: |
Oxygen Isotopic Composition of Coarse- and Fine-grained Material from Comet 81P/Wild 2 |
| Authors: |
Ogliore, Ryan C., Nagashima, Kazuhide, Huss, Gary R., Westphal, Andrew J., Gainsforth, Zack, Butterworth, Anna L. |
| Publication Year: |
2015 |
| Collection: |
Astrophysics |
| Subject Terms: |
Astrophysics - Earth and Planetary Astrophysics |
| More Details: |
Individual particles from comet 81P/Wild 2 collected by NASA's Stardust mission vary in size from small sub-$\mu$m fragments found in the walls of the aerogel tracks, to large fragments up to tens of $\mu$m in size found towards the termini of tracks. The comet, in an orbit beyond Neptune since its formation, retains an intact a record of early-Solar-System processes that was compromised in asteroidal samples by heating and aqueous alteration. We measured the O isotopic composition of seven Stardust fragments larger than $\sim$2 $\mu$m extracted from five different Stardust aerogel tracks, and 63 particles smaller than $\sim$2 $\mu$m from the wall of a Stardust track. The larger particles show a relatively narrow range of O isotopic compositions that is consistent with $^{16}$O-poor phases commonly seen in meteorites. Many of the larger Stardust fragments studied so far have chondrule-like mineralogy which is consistent with formation in the inner Solar System. The fine-grained material shows a very broad range of O isotopic compositions ($-70<\Delta^{17}$O$<+60$) suggesting that Wild 2 fines are either primitive outer-nebula dust or a very diverse sampling of inner Solar System compositional reservoirs that accreted along with a large number of inner-Solar-System rocks to form comet Wild 2. |
| Document Type: |
Working Paper |
| DOI: |
10.1016/j.gca.2015.04.028 |
| Access URL: |
http://arxiv.org/abs/1506.04783 |
| Accession Number: |
edsarx.1506.04783 |
| Database: |
arXiv |
