Bound For Mars . ... Credit Copyright: P. James ( U. Toledo ), T. Clancy ( SSI Boulder, CO ), S. Lee ( U. Colorado ), NASA Explanation: Two NASA spacecraft, Mars Global Surveyor and Mars Pathfinder , are presently approaching the red planet . ... These Hubble Space Telescope images from March 1997 show the Northern Hemisphere in early Martian summer , with a receding polar cap and whitish water-ice clouds. ... Martian weather reports will play an important role in mission planning. ...