Collecting Interplanetary Dust On Earth
In 1951, Fred Whipple predicted that micrometeorites smaller than 100 micrometers in diameter might be decelerated on impact with the Earth's upper atmosphere without melting. The modern era of laboratory study of these particles began with the stratospheric collection flights of D. E. Brownlee and collaborators in the 1970s using balloons and then U-2 aircraft.
Although some of the particles found were similar to the material in present day meteorite collections, the nanoporous nature and unequilibrated cosmic-average composition of other particles suggested that they began as fine-grained aggregates of nonvolatile building blocks and cometary ice. The interplanetary nature of these particles was later verified by noble gas and solar flare track observations.
In that context a program for atmospheric collection and curation of these particles was developed at Johnson Space Center in Texas. This stratospheric micrometeorite collection, along with presolar grains from meteorites, are unique sources of extraterrestrial material (not to mention being small astronomical objects in their own right) available for study in laboratories today.
Read more about this topic: Interplanetary Dust Cloud
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