WHEN NASA’s Mars Reconnaissance Orbiter slipped into orbit around the Red Planet last week, it joined three other illustrious probes circling Mars and two intrepid rovers on the ground that have all been studying the planet in unprecedented detail over the past two years.
While the MRO’s increased sensitivity promises a deluge of information over the next few years, its hard-working brethren have already transformed our understanding of the planet’s geological past, not least by adding a whole new epoch to Martian prehistory. This grand reappraisal of Mars’ past, thanks to the joint efforts of NASA’s Mars Global Surveyor and Mars Odyssey, its rovers Spirit and…
