Mars Reconnaissance Orbiter passes data milestone
Sen—NASA's Mars Reconnaissance Orbiter (MRO) has passed 200 terabits (equivalent to the data volume in three nonstop months of high-definition video) in the amount of science data returned since it arrived at the red planet in March 2006.
The data returned by the mission alone is more than three times the total data returned via NASA's Deep Space Network for all the other missions managed by NASA's Jet Propulsion Laboratory over the past 10 years.
The 200 terabits includes all the data MRO has relayed to Earth from robots on the surface of Mars, but about 99.9 percent of the volume has come from the six science instruments aboard the orbiter. It does not include the engineering data used for monitoring its health and performance.
"The sheer volume is impressive, but of course what's most important is what we are learning about our neighboring planet," said JPL's Rich Zurek, the project scientist for the Mars Reconnaissance Orbiter.
The orbiter's instruments have examined Mars from subsurface to atmosphere in unprecedented detail. One instrument, HiRISE (High Resolution Imaging Science Experiment) has provided images revealing features as small as a desk in surface areas equivalent to one-third of the United States (1.92 percent of Mars' surface). Another covers areas equivalent to about 82 percent of Earth's land area (83.6 percent of Mars' surface), with resolution showing features smaller than a tennis court. These cameras view many areas repeatedly, providing three-dimensional information from stereo and revealing several types of landscape changes over time. Other instruments identify surface minerals, probe underground layers, examine cross-sections of the atmosphere and track weather globally.
The High Resolution Imaging Science Experiment (HiRISE) camera. Image credit: NASA/JPL
"The mission has taught us about three very different periods of Mars history," Zurek said.
The heavily cratered terrains of Mars, the oldest on the planet, show that different types of ancient watery environments formed water-related minerals, some more favourable for life than others. More recently, water appears to have cycled as a gas between polar ice deposits and lower-latitude deposits of ice and snow. Extensive layering in ice or rock probably took hundreds of thousands to millions of years to form. The present climate is also dynamic, with volatile carbon dioxide and, possibly, flows of briny water forming dark streaks that appear in the warmest seasons and places and fade in colder weather.
"Mars Reconnaissance Orbiter has shown that Mars is still an active planet, with changes such as new craters, avalanches and dust storms," Zurek said. "Mars is a partially frozen world, but not frozen in time."
Each orbit around Mars takes the spacecraft about two hours. For part of each orbit, Mars itself usually blocks the communication path to Earth. When Earth is in view, a Deep Space Network antenna on whichever part of Earth is turned toward Mars at that hour can be listening.
The Mars Reconnaissance Orbiter mission met all its science goals in a two-year primary science phase ending in 2008. Three extensions, the latest beginning in 2012, have added to the science returns. The longevity of this mission and of NASA's even longer-lived Mars Odyssey orbiter, which has been studying Mars since 2002, have given researchers tools to study seasonal and longer-term changes on the Red Planet.