Looking inside an asteroid – a study of separated asteroid pairs

TYPEAstrophysics Seminar
Speaker:David Polishook
Organizer:Hagai Perets
Time:14:30 - 15:30
Location:Lidow 620
Abstract:The newly exciting discovered category of asteroid pairs consists of gravitationally unbound pairs that share very similar orbital elements (Vokrouhlicky & Nesvorny 2008). Studies have shown (Pravec, Vokrouhlicky, Polishook et al. 2010) that these pairs were formed by a rotational-fission event, splitting the asteroid after it rotated too fast. Since these events happened in a timescale shorter than 10^6 years, it seems that new exposed material from the interior of the asteroid can be observed.
Conducting an observing campaign of asteroid pairs we are able to show that their spectra indeed displays “fresher” features than the background population. In addition, we measured spectral variation on one of the pairs during its rotation, allowing us to disentangle different theoretical models of asteroid fission and, as a result, better understand the internal structure of asteroids. Since the dynamical age of the fission events is known, we can also constrain the timescale of the mechanism that makes asteroid spectra look “older” (the space weathering mechanism).