December 15, 2023: Speaker: David Gerdes, Chair of UM Physics Department, “Shadow of a Fossil: Stellar Occultations and NASA’s Lucy Mission to Jupiter’s Trojan Asteroids”
Jupiter’s Trojan asteroids, thousands of small icy worlds that orbit the sun 60 degrees behind or ahead of Jupiter, bear clues to our solar system’s formation history. NASA’s Lucy spacecraft, launched in October 2021, will visit 8 Trojan asteroids between 2027 and 2033. What can we learn about these elusive objects before the spacecraft arrives? I’ll discuss how stellar occultations — the total eclipse of a star by an asteroid — reveal an asteroid’s shape and size, as well as an occasional surprise. I’ll discuss occultation data for the Lucy target Polymele collected in February, 2023 by a team that included 7 U-M undergraduates, and what we have learned from it.
