Jupiter May Explain Bennu's Mixed Inner and Outer Solar System Origins

Isotope analysis of the OSIRIS-REx sample shows asteroid Bennu combines traits of both the inner and outer solar system. ETH Zurich and Lawrence Livermore researchers say it formed near the water-ice line close to Jupiter's orbit about 2 million years after the first solid rocks appeared.

• Bennu's titanium and chromium match outer-system carbonaceous asteroids, but its iron resembles inner-system bodies
• Manganese-53 dating places formation about 2 million years after the first solid rocks
• Jupiter, already 23 Earth masses, trapped millimeter chondrules at a pressure ridge near the ice line
• The sample lacks the heavy hydrogen and nitrogen seen in comets from that region