Atom & Cosmos
Clearing out space junk with dust, plus new black holes, sonic-boom star birth and more in this week’s news
By Science News
Dust to clean up space junk
Scientists have devised a controversial way to get rid of small space junk —material about 10 centimeters wide that can harm spacecraft. Gurudas Ganguli of the Naval Research Laboratory in Washington, D.C., and his colleagues propose removing the material by sprinkling about 20 tons of fine tungsten dust in a thin shell around the Earth. Atmospheric drag would force the dust to descend from an altitude of 1,100 kilometers, and the space junk would come down with it. In 10 years, all the material would fall far enough to ultimately burn up in Earth’s atmosphere, the researchers report online April 11 at arXiv.org. The team says that the dust, about 30 micrometers in diameter, wouldn’t harm spacecraft, but satellite solar arrays would need thicker cover glass. —
Ron Cowen
New class of black holes