It took seven years and a lot of picking through the Utah sand with tweezers. But scientists have finally accomplished the top goal of NASA’s Genesis mission, which flew into space in 2001 to gather particles streaming from the sun but crashed while returning them to Earth in 2004.
After painstakingly gathering and analyzing the shards, researchers report that Earth’s chemistry is not like the sun’s. Compared with the sun, the planet is enriched in two types of oxygen and one type of nitrogen, two teams report June 24 in Science.
“The big thing is that the planets around us are so different from the sun,” says Donald Burnett, a cosmochemist at Caltech and the Genesis project leader. “We have uncovered something very fundamental about how the Earth as a planet evolved.”