Science Seminars

3/19/2009 – “The life-cycles of small asteroids”

Speaker: Daniel Scheeres
Date: Thursday, Mar 19, 2009
Time: 4:00 PM
Location: LSTB

Seminar Abstract:

The recent verification that small asteroids are rubble piles and are subject the YORP effect (i.e, that solar radiation pressure makes asteroid spin rates change over relatively short time spans) has wide-ranging consequences for the life cycles of these bodies. As the spin rate of an asteroid changes, its minimum energy configuration can change and lead to profound shifts in how its mass is distributed. If the spin rate continues to increase it becomes possible for an asteroid to fission into multiple pieces, forming a binary asteroid. These proto-binary asteroids can follow several fundamentally different paths as a function of their initial morphology, including mutual escape, re-impact, and transition into a stable binary system. Recent in situ and remote observations of asteroids support this picture, and imply that the smallest members of the asteroid family lead an active and interesting life.