This ancient stardust is the oldest ever to be examined in a lab
Ancient stardust extracted from a meteorite contains specks that are up to about 3 billion years older than the solar system, making them the oldest solids ever dated in a lab, researchers report. Unlike most of the other stardust that went into building our solar system, these microscopic grains have remained intact since they were shed by aging stars billions of years ago. The exotic makeup of the silicon carbide grains, from a meteorite that landed in Australia more than 50 years ago, tipped scientists off that the minerals were older than the solar system (SN: 11/22/19). Measuring levels of neon-21 in dozens of grains revealed how much older. Neon-21 is a form of the chemical element that builds up when silicon carbide is bombarded with high-energy particles called galactic cosmic rays in interstellar space. The higher a grain’s neon-21 concentration, the longer it must have drifted in space before being embedded in a hunk of space rock during the solar system’s formation 4.6...