How scientists went to an asteroid to sample the Sun

It was, Dante Lauretta told his audience at an American Geophysical Union meeting in San Francisco, like seeing an old friend after “seven years [and] a journey of 3bn miles”. Sitting in front of him in the Utah desert on the morning of September 24th, “a little charred and worse for wear”, was a capsule about the size of a washing-machine drum. The last time he and his colleagues had seen it had been when they had packed it up ready to be launched into space from Cape Canaveral in the summer of 2016.

In the intervening years the capsule had travelled to Bennu, a small asteroid in an orbit which crosses that of the Earth, as part of a mission called OSIRIS REx. In 2020 the mission’s main spacecraft briefly descended to Bennu’s surface and loaded the capsule with perhaps 140g of material. It then returned to the vicinity of the Earth, cast off the capsule and flew off to study another asteroid named Apophis. The capsule plunged into the atmosphere like an incoming meteorite; it failed to deploy its parachute in the way that had been planned (thus giving Dr Lauretta conniptions) but ended up safe and sound on the surface.