A Possible Explanation for the Presence of Crystalline H2O-Ice on Kuiper Belt Objects
Icarus 351 (2020) 113943 Contents lists available at ScienceDirect Icarus journal homepage: www.elsevier.com/locate/icarus A possible explanation for the presence of crystalline H2O-ice on Kuiper Belt objects Mark J. Loeffler a,b,*, Patrick D. Tribbett a, John F. Cooper c, Steven J. Sturner d,e a Department of Astronomy and Planetary Science, Northern Arizona University, Flagstaff, AZ 86011, United States of America b Center for Materials Interfaces in Research and Applications, Northern Arizona University, Flagstaff, AZ 86011, United States of America c Heliospheric Physics Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, United States of America d Goddard Planetary Heliophysics Institute, University of Maryland, Baltimore County, Baltimore, MD 21228, United States of America e Astroparticle Physics Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, United States of America ARTICLE INFO ABSTRACT Keywords: The detection of crystalline H2O-ice on multiple surfaces of Kuiper Belt Objects (KBOs) seems to contrast with Astrochemistry what scientists understand about the surface environment of these objects, as previous estimates suggest that Cosmic rays radiolysis should have easily amorphized these objects’ surface over their lifetimes. Here, we use a detailed Experimental techniques laboratory approach to show that crystalline H2O-ice can be amorphized by energetic electrons at temperatures Ices, IR spectroscopy as high as 70 K. However, the estimated time needed to completely amorphize the H O-ice present on the surface Kuiper belt 2 of a KBO to the depth probed by near-infrared spectroscopy is only slightly less than the age of the solar system. Given the uncertainties involved in these types of extrapolations and the possibility of a resurfacing event occurring in these objects lifetime, the detection of crystalline or at least partially crystalline H2O-ice on KBOs should be expected.
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