Stardust Interstellar Preliminary Examination VII: Synchrotron X-ray fluorescence analysis of six Stardust interstellar candidates measured with the Advanced Photon Source 2-ID-D microprobe
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1
George J. Flynn
- Function : Author
Steven R. Sutton
- Function : Author
Barry Lai
- Function : Author
Sue Wirick
- Function : Author
Carlton Allen
- Function : Author
David Anderson
- Function : Author
- PersonId : 772210
- ORCID : 0000-0001-6175-3872
Asna Ansari
- Function : Author
Saša Bajt
- Function : Author
Ron K. Bastien
- Function : Author
Nabil Bassim
- Function : Author
Hans A. Bechtel
- Function : Author
Janet Borg
- Function : Author
Frank E. Brenker
- Function : Author
John Bridges
- Function : Author
Donald E. Brownlee
- Function : Author
Mark Burchell
- Function : Author
Manfred Burghammer
- Function : Author
Anna L. Butterworth
- Function : Author
Hitesh Changela
- Function : Author
Peter Cloetens
- Function : Author
Andrew M. Davis
- Function : Author
Ryan Doll
- Function : Author
Christine Floss
- Function : Author
David Frank
- Function : Author
Zack Gainsforth
- Function : Author
Eberhard Grün
- Function : Author
Philipp R. Heck
- Function : Author
Jon K. Hillier
- Function : Author
Peter Hoppe
- Function : Author
Bruce Hudson
- Function : Author
Joachim Huth
- Function : Author
Brit Hvide
- Function : Author
Anton Kearsley
- Function : Author
Ashley J. King
- Function : Author
Jan Leitner
- Function : Author
Laurence Lemelle
- Function : Author
- PersonId : 741597
- IdHAL : laurence-lemelle
- ORCID : 0000-0002-7082-5564
- IdRef : 191491675
Hugues Leroux
- Function : Author
Ariel Leonard
- Function : Author
Robert Lettieri
- Function : Author
William Marchant
- Function : Author
Larry R. Nittler
- Function : Author
Ryan Ogliore
- Function : Author
Wei Ja Ong
- Function : Author
Frank Postberg
- Function : Author
Mark C. Price
- Function : Author
Scott A. Sandford
- Function : Author
Juan-Angel Sans Tresseras
- Function : Author
Sylvia Schmitz
- Function : Author
Tom Schoonjans
- Function : Author
Geert Silversmit
- Function : Author
Alexandre Simionovici
- Function : Author
- PersonId : 756970
- ORCID : 0000-0001-5349-6482
Vicente A. Sol
- Function : Author
Ralf Srama
- Function : Author
Frank J. Stadermann
- Function : Author
Thomas Stephan
- Function : Author
Veerle Sterken
- Function : Author
Julien Stodolna
- Function : Author
Rhonda M. Stroud
- Function : Author
Mario Trieloff
- Function : Author
Peter Tsou
- Function : Author
Akira Tsuchiyama
- Function : Author
Tolek Tyliszczak
- Function : Author
Bart Vekemans
- Function : Author
Laszlo Vincze
- Function : Author
Joshua Von Korff
- Function : Author
Andrew J. Westphal
- Function : Author
Naomi Wordsworth
- Function : Author
Daniel Zevin
- Function : Author
Michael E. Zolensky
- Function : Author
Abstract
The NASA Stardust spacecraft exposed an aerogel collector to the interstellar dust passing through the solar system. We performed X-ray fluorescence element mapping and abundance measurements, for elements 19 <= Z <= 30, on six "interstellar candidates," potential interstellar impacts identified by Stardust@Home and extracted for analyses in picokeystones. One, I1044,3,33, showed no element hot-spots within the designated search area. However, we identified a nearby surface feature, consistent with the impact of a weak, high-speed particle having an approximately chondritic (CI) element abundance pattern, except for factor-of-ten enrichments in K and Zn and an S depletion. This hot-spot, containing approximately 10 fg of Fe, corresponds to an approximately 350 nm chondritic particle, small enough to be missed by Stardust@Home, indicating that other techniques may be necessary to identify all interstellar candidates. Only one interstellar candidate, I1004,1,2, showed a track. The terminal particle has large enrichments in S, Ti, Cr, Mn, Ni, Cu, and Zn relative to Fe-normalized CI values. It has high Al/Fe, but does not match the Ni/Fe range measured for samples of Al-deck material from the Stardust sample return capsule, which was within the field-of-view of the interstellar collector. A third interstellar candidate, I1075,1,25, showed an Al-rich surface feature that has a composition generally consistent with the Al-deck material, suggesting that it is a secondary particle. The other three interstellar candidates, I1001,1,16, I1001,2,17, and I1044,2,32, showed no impact features or tracks, but allowed assessment of submicron contamination in this aerogel, including Fe hot-spots having CI-like Ni/Fe ratios, complicating the search for CI-like interstellar/interplanetary dust.