Dissemin is shutting down on January 1st, 2025

Published in

American Astronomical Society, Astrophysical Journal Letters, 1(924), p. L9, 2022

DOI: 10.3847/2041-8213/ac415a

Links

Tools

Export citation

Search in Google Scholar

The Appearance of a “Fresh” Surface on 596 Scheila as a Consequence of the 2010 Impact Event

This paper is made freely available by the publisher.
This paper is made freely available by the publisher.

Full text: Download

Red circle
Preprint: archiving forbidden
Red circle
Postprint: archiving forbidden
Green circle
Published version: archiving allowed
Data provided by SHERPA/RoMEO

Abstract

Abstract Dust emission was detected on main-belt asteroid 596 Scheila in 2010 December and was attributed to the collision of a few-tens-of-meters projectile on the surface of the asteroid. In such an impact, the ejected material from the collided body is expected to mainly come from its fresh, unweathered subsurface. Therefore, it is expected that the surface of 596 was partially or entirely refreshed during the 2010 impact. By combining spectra of 596 from the literature and our own observations, we show that the 2010 impact event resulted in a significant slope change in the near-infrared (0.8–2.5 μm) spectrum of the asteroid, from moderately red (T type) before the impact to red (D type) after the impact. This provides evidence that red carbonaceous asteroids become less red with time due to space weathering, in agreement with predictions derived from laboratory experiments on the primitive Tagish Lake meteorite, which is spectrally similar to 596. This discovery provides the very first telescopic confirmation of the expected weathering trend of asteroids spectrally analog to Tagish Lake and/or anhydrous chondritic porous interplanetary dust particles. Our results also suggest that the population of implanted objects from the outer solar system is much larger than previously estimated in the main belt, but many of these objects are hidden below their space-weathered surfaces.