Phoenix Lander's microphone may record what Mars sounds like

Washington, Oct 3 : NASA scientists are hoping to hear what Mars sounds like when they attempt to switch on the Phoenix Mars Lander's microphone in the next week or two.

Phoenix's microphone is a part of the Mars Descent Imager system (MARDI) that was included on the underside of the lander to take downward-looking images during the three minutes of descent before the spacecraft touched down on the planet's surface.

The MARDI on Phoenix was originally designed for the Mars Surveyor 2001 Lander missions, which were eventually canceled.

The plan to use the imager and microphone on May 25, when Phoenix landed, were scrapped when tests showed that using the system would create an unacceptable risk to a safe landing for Phoenix.

Phoenix did safely land at its appointed side in the Martian arctic, where it has been digging up samples of dirt and subsurface water ice and analyzing them with its instruments to assess the planet's past potential habitability.

Though the original plan to use Phoenix's mike during landing was scrapped, mission scientists didn't rule out using it later during the mission.

"We'd always hoped to turn it on," said Phoenix principal investigator Peter Smith.

The team needed NASA's approval for funding to turn on the microphone, and now they've gotten the go-ahead, Smith added.

"They can't flip the switch right away. There are still a few checks that need to be done, and Phoenix's software needs to be changed a bit," Smith told Space.com. "We're just kind of cranking it up," he added.

Once all the preparations are ready, the team plans to try to turn the microphone on while the lander is digging or using the rasp on the end of its robotic arm scoop, "just to make sure we hear something," Smith said.

"You at least want to know if there's a chance of noise being created," he added.

Phoenix scientists aren't sure just what, or how much, they'll hear. For one thing, Phoenix's mike is "not a professional microphone," according to Smith.

For another, sound waves don't travel as far on Mars as they do on Earth because Mars' atmosphere is thinner.

"It would be similar to listening to sound at an altitude of about 100,000 feet (30,500 meters) above Earth's surface," Smith said.

If the team can hear Phoenix's operations, they'll then turn the microphone on while Phoenix is quiet and just see what they can hear.

ANI