“I Can See the Lander from Here…”
Spotting Evidence of Human Exploration of Mars
As the Mars Phoenix lander started to get a glimpse of the Sun towards the end of the northern hemisphere winter, the Mars Reconnaissance Orbiter's HiRISE camera was used to image the Phoenix landing site despite the low light levels. (Courtesy NASA/JPL/University of Arizona)
Back in late (Earth) summer, the Mars Reconnaissance Orbiter HIRISE Camera (MOR-HIRISE) took an image of an area near the north pole of Mars. It shows that the region looks like a frigid wasteland — which it is during Mars winter. But, smack in the middle of the image is something kinda neat — the Mars Phoenix Lander — standing out against the background terrain.
Phoenix was sent to measure conditions for a short time near the pole. It performed quite well before going to sleep during the onset of northern hemisphere winter. For now it is dormant and quite possibly dead. Scientists are going to try and communicate with it as spring approaches. In the meantime, though, the MRO continues to study the surface in the polar regions to help us understand what sorts of changes it goes through during the yearly freeze and thaw cycle.
In this portion of the larger image returned by the HIRISE camera, the large expanse of white area doesn’t actually doesn’t indicate the amount of frost surrounding the lander. Since this image was taken in a low-light situation, its bright and dark values have been stretched to bring out the contrast and allows us to see details in the surface near the lander. Many factors affect how the surface looks in an image. Scientists need to take into account the size of carbon dioxide ice grains mixed in with the surface soil, the amount of dust mixed in with the ice, the amount of sunlight hitting the surface, and different lighting angles and slopes. In addition, the winds blow here constantly, and their directions change all the time. Depending on how strong the winds are,they can move loose frost and dust around, changing the way the surface looks. Studying these changes will help planetary scientists understand the nature of the seasonal frost and winter weather patterns in this area of Mars.
I think it’s pretty amazing we can spot evidence of our robotic exploration on Mars. So far as the evidence from the various mappers and orbiters have shown us, humans are the ONLY ones to have explored Mars in its history — and that makes this pretty darned unique!
