Bennu Samples Point to Origin Near Ice Line Filtered by Jupiter

An ETH Zurich study in Science Advances finds that asteroid Bennu formed near the water-ice line at 2–3 AU from the Sun, not in the outer solar system. Isotope measurements of iron, titanium and chromium in a half-gram of the OSIRIS-REx sample reveal a hybrid composition shaped by Jupiter's gravitational filtering of fine dust.

• Bennu formed near the water-ice line at 2–3 AU, not in the outer solar system
• Bennu's isotopes match Ryugu and CI chondrites
• Jupiter blocked coarse pebbles while fine dust mixed inward
• OSIRIS-REx returned 121.6 grams of Bennu material in 2023