Orbiter Catches Sounds from Phoenix Mars Descent
Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment (HiRISE) camera acquired this image of Phoenix hanging from its parachute as it descended to the Martian surface. Although it appears that Phoenix is descending into the crater, it is actually about 20 kilometers (about 12 miles) in front of the crater.
Credit: NASA/JPL-Caltech/University of Arizona

This story was updated at 1:10 pm EDT.

A European spacecraft caught sounds from NASA?s Phoenix Mars Lander during its screaming Sunday descent to the red planet?s arctic surface.

The European Mars Express beamed the audio data to Earth shortly after NASA?s Phoenix Mars Lander touched down in the Martian arctic late Sunday. The signal from Phoenix?s descent comes through loud and clear after processing by the Mars Express Flight Control Team.

A shift occurred in the signal received by Mars Express due to the so-called Doppler Effect, not unlike hearing the whistle of a passing train, as the orbiter moved away from the lander.

Mars Express successfully tracked Phoenix throughout descent using the Mars Express Lander Communication system (MELACOM), even during the expected transmission blackout window when ionization builds up around the lander as it falls through the atmosphere.

The signal finally cut out as Mars Express flew away and the lander passed out of view. NASA?s Mars Odyssey and Mars Reconnaissance Orbiter also watched over Phoenix?s successful landing.

Phoenix is equipped with a microphone that was originally slated to record sounds during landing in conjunction with a camera designed to take aerial photographs of the probe?s arctic landing site. While that plan was scrapped to avoid complications with Phoenix?s landing, the microphone may still be used on the surface, mission managers said.

?We?d all love to hear some noises from the surface of Mars, that would be a first," said Phoenix principal investigator Peter Smith of the University of Arizona.

The $422 million Phoenix lander is a stationary probe equipped with a scoop-tipped robotic arm to search for buried water ice beneath the arctic plains of its Vastitas Borealis landing site. The spacecraft carries a Canadian-built weather station, ovens and wet chemistry lab, and is designed to study Mars for at least three months to determine if the planet?s arctic circle could have once supported primitive life.

Mars Express will continue monitoring Phoenix by using MELACOM fifteen more times. That should help demonstrate that the European Space Agency?s spacecraft can relay data from the Martian surface to Earth, and also transmit commands from Earth to the lander.

Editor?s Note: This report has been changed to clarify that the Doppler Effect applies to a shift in signal transmitted by Phoenix and received by Mars Express.