New instrument may detect groundwater deep inside Mars

Washington, June 25 (ANI): A team of Boulder (US) scientists and engineers has tested a new instrument prototype that might be used to detect groundwater deep inside Mars.

Known as the Mars Time Domain Electromagnetic Sounder (MTDEM), the instrument uses induction to generate electrical currents in the ground, whose secondary magnetic fields are in turn detected at the planetary surface.

In this way, the electrical conductivity of the subsurface can be reconstructed.

"Groundwater that has been out of atmospheric circulation for eons will be very salty," said the project's principal investigator Dr. Robert Grimm, a director in the Space Science and Engineering Division at Southwest Research Institute. "It is a near-ideal exploration target for inductive systems," he added.

The inductive principle of the MTDEM is distinct from the wavelike, surface-penetrating radars MARSIS and SHARAD presently orbiting Mars.

"The radars have been very useful in imaging through ice and through very dry, low-density rock, but they have not lived up to expectations to look through solid rock and find water," said Grimm.

The time-domain inductive method uses a large, flat-lying loop of wire on the ground to generate and receive electromagnetic signals.

In order to do this robotically, the team developed a launch system that shoots two projectiles, each paying out spooled wire as they fly.

Data taken during the test launches allowed Warden and Grimm to scale the system for a flight mission. The MTDEM prototype deployed to a distance of more than 70 meters.

For Mars, a system deploying a 200-meter loop would be less than 6 kilograms mass and could detect groundwater at depths up to 5 kilometers (3 miles). Most of the instrument's mass would be in the loop and deployment system.

According to Barry Berdanier, the Ball electrical engineer who built the MTDEM electronics, the flight electronics would comprise just a few hundred grams.

"Electromagnetic induction methods are widely used in groundwater exploration," said James Pfieffer of Zapata Incorporated, a geophysical firm that provided field support.

"Subsurface, liquid water on Mars could be a habitable zone for microbes. We know that huge volumes of discharged groundwater have shaped Mars' ancient surface," said Grimm. (ANI)