Forgetting for a moment the two high-profile mission failures that recently marred NASA’s Mars program, 1999 was actually a remarkable year for discovery about Mars, many leading planetary scientists say. Evidence is steadily streaming in from the Mars Global Surveyor that the planet may have been underestimated. Far from being the dead, cold, simple planet it has often been thought of, Mars seems to have had a complex, dynamic past, with an active iron core that produced a strong magnetic field, and a surface covered with huge oceans and perhaps even hot springs.