The NASA's Mars rovers Spirit and Opportunity continue to persevere in hard conditions. It is clearly visible in images of the sun they are sending. The images show how opaque the Martian atmosphere has been in the face of a very active, two-month dust storm.
To understand the gravity of the storm, engineers and astronomers monitored the situation by examining the images and measuring the amount of dust or the opacity of the atmosphere.
Emily Lakdawalla of the Planetary Society assembled a mosaic of images, which were taken daily by the panoramic cameras (Pancams) on both rovers.
The images were calibrated by students in Cornell's MarsLab image-processing facility and made available through collaboration with Jim Bell, Cornell professor of astronomy and the principal investigator on the rovers' Pancam imaging team. He said that the mosaics show a rover's-eye view of the storm getting worse, and the sun getting dimmer and dimmer as the dust clouds built up.
Since June, a massive dust storm has put the rovers in danger, as they depend upon solar power to run during the day and to survive the uncomfortable Martian nights. As dust clouds block the sunlight and dust settles on the solar panels, the rovers' energy is depleted.
For Spirit, the Jet Propulsion Laboratory, Pasadena, California, reports that even though the Martian sky above Gusev Crater is clearing, solar power levels remained fairly low and constant dust now appears to be accumulating on the solar panels. Between sol, which is the Martian day, 1283 (12 August) and sol 1286 (16 August), the atmosphere cleared by nearly 35 percent, leading to daily energy levels of about 300 watt-hours. Typical levels before the dust storms were around 700 to 900 watt-hours.
On the other side of Mars, Opportunity, waiting to enter Victoria Crater, is now experiencing its lowest power levels to date. The sky was so dark in the middle of July that less than 200 watt-hours of daily energy was available. Skies are slowly clearing, offering hope that the rover will be ready for a descent into the crater soon.
The Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, manages the Mars Exploration Rover Project for the NASA Science Mission Directorate, Washington, DC.