Mars Rover Data Hopeful
NASA’s Opportunity rover rolled off its lander early Saturday morning, but before it did so it sent back preliminary data hinting that its search for signs of ancient water on the Martian surface would be successful.
Early returns from the craft’s thermal emission spectrometer indicate not only that the gray granules on the surface of the craft’s landing site in Meridiani Planum contain the iron oxide mineral hematite, but also that they have trace concentrations of other minerals indicating the hematite was formed in water at low temperatures -- that is, in the sediments of a lake bed.
Confirming that finding will require that the rover get “down and dirty” in the Martian soil, officials said. Opportunity made a major step toward that goal Saturday, rolling off the lander at 1:51 a.m., although confirmation of its success did not make it back to Pasadena’s Jet Propulsion Laboratory until 3:01 a.m. in a data relay through the Mars Odyssey orbiter.
“We’re two for two! One dozen wheels on the soil,” said flight director Chris Lewicki as cheers erupted at JPL.
Opportunity rolled onto Martian soil a week after it arrived on the planet and less than a month after its twin, Spirit, landed halfway around Mars at Gusev Crater on Jan. 3.
Opportunity took 83 seconds to make the 10-foot drive off the lander, parking about a yard away from the now useless machinery that carried it on its seven-month trip to the Red Planet.
The lander was not as stable a platform as had been expected, tilting a little to the right as the rover moved forward before descending. Although that didn’t create a problem, the rover’s tracks in an image taken after egress showed the trail veering about seven degrees to the right.
“That was probably the scariest part of the drive we will have on Mars,” said mission manager Jim Erickson.
The early roll-off occurred because the team encountered fewer surprises in prepping the craft for its mission than they had with Spirit. “Mars threw us fewer curve balls than last time,” said activity leader Joel Krajewski. Also, he added: “We’re getting practiced at it.”
The team will spend the next day or two “doing a little bit of cleanup,” said flight director Chris Salvo. “We have some loose ends to tie up.”
While engineers are doing that, scientists will begin deploying the craft’s spectrometers to examine the soil for a couple of days.
“Then we’ll cruise the outcrop,” a layer of exposed white rock that geologists hope will reveal the history of the small crater in which Opportunity rests.
Even before the craft rolled off the lander, it used its thermal emission spectrometer, a device the scientists call mini-TES, to examine the soil in the region.
“Mini-TES has indeed discovered hematite on the surface of Mars,” said geologist Phil Christensen of Arizona State University. “This is a huge first step.”
The two rovers were sent to Mars on the $820-million mission to look for signs of surface water on Mars when the planet was young, a necessary precursor for the existence of life. The low-temperature origin of the hematite is promising, Christensen said, “But we are still a long way from proving” the existence of large quantities of surface water.
The mini-TES measurements showed one very interesting piece of data, he noted.
Earlier pictures showed distinct impressions made by the lander’s air bags when the craft bounced to a landing in its small crater. When scientists focused mini-TES on these impressions, which are much brighter than the surrounding soil, it detected no hematite.
Scientist have been fervently arguing about what happened to the hematite, especially since none of the soil adhered to the surface of the air bags. They say it’s most likely that the hematite is contained in coarse grains that were squeezed down into the soil when the lander bounced.
