Notes from a panel at Capricon 44, Chicago, Feb. 2, 2024. Any mistakes are mine. The panelists are not responsible for any errors here.

Bill Higgins, Henry Spencer

The OSIRIS-REx asteroid sampler has returned with a bounty of asteroid dust. Our panelists discuss what the findings have been so far, what is still to come, and what it all means.

This was a mission to the asteroid Bennu. There is not much news about the scientific results yet. The idea was to retrieve samples that had not been contaminated by Earth, unlike most meteorites. Hence a fresh sample from an asteroid.

• Japan has had two successful asteroid sample return missions. Hayabusa went to the asteroid 25143 Itokawa and Hayabusa2 flew to 162173 Ryugu.

• Bennu and Ryugu both turned out to be unexpectedly rocky, which complicated the task of finding landing sites. The ground was more like gravel than sand.

• Bennu is a class B, carbon rich, asteroid

• 25% of the samples returned from Bennu will be analyzed immediately. The rest will be saved for the future, when (hopefully) there will be better instruments and techniques to analyze them.

• There are some unexplained particle ejections from Bennu.

• Every asteroid is different.

• Change is everywhere. We are not really getting a pristine sample of the early solar system.

• TAGSAM: OSIRIS-REx used a Touch-and-Go Sample Acquisition Mechanism.

• Having successfully returned its sample payload to Earth, the spacecraft, renamed OSIRIS-APEX has been redirected to the asteroid 99942 Apophis, which it will reach in 2029. The orbit of Apophis will bring it within 20,000 miles/32,000 kilometers of Earth, inside of geostationary satellite orbits