Astrometric Reduction of the Mars Exploration Rover Night-Time Observations of Phobos and Deimos
Résumé
In 2003 NASA launched toward Mars two robots, Spirit and Opportunity, in search of answers about the history of water on Mars. They landed on Mars on January 4 and January 24, 2004. Since this date, they have traversed around their landing site to search for and characterize a wide range of rocks and soils that hold clues to past water activity on Mars. Among the science instruments carried by the rovers, the Panoramic Camera (Pancam) is used to determine the mineralogy, the texture, and the structure of the local terrain. The Pancam has also been used to take images of the martian sky during the night. In particular, the Spirit rover has taken more than 500 night-time images showing Mars's moons Phobos and Deimos. We are performing the astrometric reduction of those images, with the goal of refining further the ephemerides of both satellites.