Written by Derek Kessler on
Wednesday, 28 May 2008
In a remarkable coincidence, the Mars Reconnaissance Orbiter was passing over the landing area for the Phoenix lander on Sunday. The satellite continued to snap pictures as it went overhead, capturing an unprecedented image of the lander and parachutes from orbit. This was the first time that any orbiting spacecraft has captured the landing of another, on any planet.
The MRO was orbiting Mars at about 760 km altitude at the time. In the photo, you can see Phoenix’s 10-meter wide parachute with the lander itself hanging below (and dragging the chute down with it).
Phoenix’s parachute was deployed at 12.6 km over the Martian surface, at which time the lander was plummeting to the surface at 2000 kph (Mach 1.7 on Earth). The parachute deployed about 6.5 seconds later than the engineers had expected, causing the craft to hurtle through the atmosphere unabated for that much longer and pushing back the actual landing site to the far end of the targeted drop zone.
The polygonal cracks and troughs in the arctic soil around Phoenix are indicative of water ice below the surface.
Since landing and deploying its solar arrays, Phoenix has sent back many more images from the surface of the Martian arctic. The flat pebble-strewn landscape is laced with polygonal cracks and troughs that are indicative of the contraction and expansion of water ice beneath the surface. Because the cracks aren’t entirely filled in with soil from the dust storms that routinely blanket large portions of Mars, the presence of cracks means that they have formed recently due to still-active arctic soils.
In a remarkable coincidence, the Mars Reconnaissance Orbiter was passing over the landing area for the Phoenix lander on Sunday. The satellite continued to snap pictures as it went overhead, capturing an unprecedented image of the lander and parachutes from orbit. This was the first time that any orbiting spacecraft has captured the landing of another, on any planet.
