Free Astronomy Magazine March-April 2021

6 MARCH-APRIL 2021 MARS ROVERS T he mission launch took place on December 4, 1996, landing on Mars on July 4, 1997. Mars Pathfinder not only achieved its goal, but also returned an unprecedented amount of data while far exceeded the primary mission’s uptime. Both the lander and the rover, named So- journer, carried instruments for both scientific observations and to provide engineering data on the new tech- nologies being demonstrated during the mission. Mars Pathfinder used an innovative method to directly enter the Martian atmosphere, assisted by a parachute to slow the early descent through the thin atmosphere and then a giant airbag system to cushion the impact. The landing site, an an- cient floodplain in the northern hemi- sphere of Mars known as Ares Vallis , is among the rockiest regions of Mars. It was chosen because scientists believed it was a relatively safe surface to land on and because it contained a wide variety of rocks possibly deposited during an ancient catastrophic flood. Sojourner T he Sojourner rover and undeployed ramps onboard the Mars Pathfinder spacecraft can be seen in this image, by the Imager for Mars Pathfinder (IMP) on July 4, 1997, (sol 1). [NASA/JPL] M ars Pathfinder “Filled Donut” mosaic, made of 3 data sets: (1) a color mosaic image of the “Gallery Panorama,” (2) an image which indicates the distance to the nearest object at each pixel location, re- ferred to as a range image, and (3) a digital image of a full-scale museum model of the MPF Lander. [NASA/JPL]