Mars probe Phoenix loses a day of work due to data glitch

The Phoenix lander stopped digging soil near Mars' north pole Wednesday as engineers on Earth worked to fix a glitch that caused the loss of a day's worth of photos.

The problem was discovered late Tuesday after the spacecraft dug a trench inside a polygon-shaped surface feature that was likely caused by seasonal expansion and shrinking of ice.

The lander beamed back pictures of the trench, but an overload of data prevented it from saving images of the landscape and atmosphere in its flash memory.

Engineers noticed Phoenix's strange behavior when it sent a piece of engineering data 45,000 times like a broken record. Normally, the lander would store the day's work in its flash memory, but the repeated data caused it to power down for the night without saving everything.

Engineers overcame the bug, but its cause remained unknown. Wednesday's digging was delayed to not stress Phoenix's memory.

"It's unfortunate to lose any bit of science," said mission scientist Ray Arvidson of Washington University in St. Louis. "But it's not really critical stuff that you kick yourself over."

Before the glitch, Phoenix dug a footlong trench less than an inch deep, but didn't find any of the white material present in deeper trenches. Scientists think Phoenix will reach the white material — possibly ice or salt — as it digs deeper Thursday.