STARDUST: Composition of Wild-2 Samples
Abstract
On Jan 2 2004 NASA s Stardust spacecraft flew through the coma of comet Wild-2 capturing particles in a low-density silica aerogel collector The objective was to capture 1 000 particles 10 micrometers in size Stardust delivered the samples to Earth on Jan 15 2006 A description of the collection and the capture cells is in Tsou et al 1 Wild-2 is a short-period comet believed to have originated in the Kuiper Belt Thus analysis of Wild-2 dust provides the first opportunity to probe conditions in the Kuiper Belt during dust formation and compare them with conditions in the asteroid belt as inferred from primitive meteorites In preparation for the Stardust return F H o rz NASA JSC shot dust from the Allende meteorite and a microprobe standard unknown into aerogel cells Samples of both were provided to each group participating in Stardust composition preliminary examination Allende provides an indication of the elements each instrument can detect in a chondritic sample while the unknown insures consistency in analyses among the laboratories on 4 continents that are participating in the examination In the ideal case aerogel capture results in gentle deceleration giving a single terminal particle at the end of a conical track whose length is a few hundred times the diameter of the particle However weak material e g the Murchison carbonaceous meteorite shot into aerogel at sim 6 km s comparable to the Stardust encounter with Wild-2 frequently leaves many fragments along the track Capture results in accretion
- Publication:
-
36th COSPAR Scientific Assembly
- Pub Date:
- 2006
- Bibcode:
- 2006cosp...36..579F