Phoenix Lander Survives First Martian Dust Storm

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NEW YORK — NASA’s Phoenix Mars Lander weathered its first dust storm on the red planet Oct. 11-12, though the dust did lower the amount of solar power available for the lander and put the brakes on some of its planned activities.

Phoenix project manager Barry Goldstein of NASA’s Jet Propulsion Laboratory told reporters about the events during a lecture discussing the mission at the Popular Mechanics Breakthrough Conference here Oct. 15.

The storm, which covered nearly 37,000 square kilometers, moved west to east around the northern arctic plains of Mars, and weakened considerably by the time it reached the lander Oct. 11. NASA’s Mars Reconnaissance Orbiter, which is circling the planet, took a snapshot of the storm as it blew over Phoenix.

At the height of the storm, all the dust it had kicked up increased the opacity of the atmosphere above the spacecraft, letting less sunlight through to its solar arrays, the lander’s sole source of power.

Phoenix’s power levels “really dropped drastically,” Goldstein said.

The hit to the lander’s already diminishing power supplies limited what the spacecraft could do during the weekend.

Phoenix landed on Mars May 25 and has spent more than four months studying the planet’s arctic plains. During that time it has scooped up samples of dirt and subsurface water ice found at its landing site, and analyzed them for signs that Mars might have been habitable in the past.

The Phoenix mission team tracked the dust storm through images gleaned from the Mars Reconnaissance Orbiter’s Mars Color Imager.

Before the storm hit, Phoenix was generating about 2,100 watt-hours each sol, or martian day, but that number dropped by about a couple hundred watt-hours during the height of the storm. By Oct. 15 power levels had rebounded back to about 2,100 watt-hours, Goldstein said.

Phoenix already is generating less energy each sol than it was earlier in the mission because the sun is dipping lower and lower in the martian sky as winter nears.

This storm might not be the last that Phoenix experiences because local dust storms tend to pop up more during fall and winter in the martian arctic.

The storms are not the global monsters experienced by the Mars Exploration Rovers, Goldstein said, but are smaller regional dust storms. If other storms hit the lander, they’ll further limit Phoenix’s abilities to finish filling the ovens in its Thermal and Evolved-Gas Analyzer, as well as other activities, before it finally loses all power.