Indian Mars-Colour-Camera captures far-side of the Deimos: A rarity among contemporary Mars orbiters

Abstract

Mars and Deimos are tidally locked so one would always get to view the same side of Deimos from Mars. Most of the contemporary functional satellites orbiting Mars viz. Mars Reconnaissance Orbiter , Mars Express, Mars Odyssey, MAVEN etc. are positioned between Mars and Deimos, hence they always view only one side of Deimos i.e the Mars-side, while the far-side is always looking outward with respect to all these satellites. However the maiden Indian Mars Orbiter Mission (MOM) is an exception as it has a very large elliptical orbit and goes behind the orbit of Deimos. This has enabled MOM to view the far-side of Deimos which has not been viewed for last few decades by any Mars orbiter. Mars Colour Camera (MCC), onboard MOM acquired four image-frames of the Deimos, the farthest of two natural satellites of Mars, on October 14, 2014 at around 13:05 UT. These four images of MCC have been used to generate an High Dynamic Range (HDR) product so as to enhance the image details. The two well-known craters of near-side are missing in this HDR image and the shape of far-side, recently updated and reported models of Deimos proposed by other researchers, matches with the shape of Deimos in MCC images thus confirming that the far-side view of Deimos has been captured by MCC of Mars Orbiter Mission. The magnitude of Deimos has also been computed from this far-side image, which varies by a small margin from the known magnitude of Deimos. This could probably be due to possible difference in the near and far side surface characteristics, which needs further detailed investigation and more imaging of far-side in future. However, there could be reasons other than the physical characteristics of the Deimos. Thus far-side sighting has generated a scientific interest to understand it holistically. This note is a brisk or rapid communication regarding sighting of the far-side of the Deimos by MCC after a long spell of more than three decades by any other Mars mission, including the contemporary operational Mars orbiters. It highlights the imaging capabilities of MCC-MOM and possible research to come in future.