Presentation
“Lucy: The First Mission to the Trojan Asteroids” by Dr. John Spencer, SWRI
Summary
The Trojan asteroids share Jupiter’s orbit in two vast swarms, on ahead of Jupiter and one behind. They are nearly as numerous as the main-belt asteroids between Mars and Jupiter, but appear to be different in composition, having formed further from the sun. They have yet to be explored by spacecraft, but NASA’s Lucy mission is about to change that. Launched in 2021, Lucy will fly by five Trojan asteroids and their moons between 2027 and 2033, returning high-resolution images and compositional data. The talk will provide a preview of what the mission will accomplish, and describe results from Lucy’s “practice” flybys of the main belt asteroids Dinkinesh and Donaldjohanson, in November 2023 and April 2025.
Bio
John Spencer is an Institute Scientist at the Southwest Research Institute in Boulder, and is the Deputy Project Scientist on the Lucy Mission. He specializes in studies of small bodies in the outer solar system using ground-based telescopes, the Hubble Space Telescope, and interplanetary spacecraft. He is also a member of the science team on the Europa Clipper mission, and has worked on the science teams for the Galileo, Cassini, and New Horizons missions. His work has included the first observations and composition measurements of Io’s volcanic plumes with Hubble, discovery that Io’s atmosphere is asymmetrical and varies seasonally, and co-discovery of cryovolcanic activity on Saturn’s moon Enceladus.
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