The Breath of the Solar System's Birth
Most of the Genesis payload consisted of fragile solar-wind collectors, which had been exposed to the solar particles over a period of two years. Nearly all of these collectors were decimated during the crash. But the capsule also contained a special instrument built by a team at Los Alamos National Laboratory to enhance the flow of solar wind onto a small target to make possible oxygen and nitrogen measurements. The targets of this Solar Wind Concentrator survived the crash and eventually yielded solar secrets.
The results provide new clues to how the Solar System was formed. Oxygen and nitrogen samples collected from various meteorites, as well as nitrogen sampled in lunar soil and in the Jupiter atmosphere by the Galileo probe, vary significantly from that on Earth by cosmochemical standards: 38 percent for nitrogen and up to 7 percent for oxygen. With the first solar wind samples in hand, showing the early Sun’s composition, scientists can begin the game of determining where Earth’s different O and N came from.
"For nitrogen, Jupiter and the Sun look the same," said Wiens. "It tells us that the original gaseous component of the inner and outer solar system was homogeneous for nitrogen, at least. So where did Earth gets its heavier nitrogen from? Maybe it came here in the material comets are made of. Perhaps it was bonded with organic materials."
The Science papers are titled "A 15N-poor isotopic composition for the solar system as shown by Genesis solar wind samples" and "The oxygen isotopic composition of the Sun inferred from captured solar wind." Wiens is among several collaborating authors on both papers, which together are cover stories for this issue. Other LANL coauthors, Beth Nordholt and Ron Moses, along with former LANL scientist Dan Reisenfeld, were all part of the team to develop and fly the Solar Wind Concentrator that provided the samples for the studies reported in Science.
And now that some of the particles flowing past Earth from the Sun are in hand, "It’s going to make a mission to a comet all the more interesting," Wiens said.