By Xinhua,
Beijing : A space-based radar aboard a European Mars probe could not only peer under the frozen extraterrestrial seas of moons such as Europa and Titan, but also see beneath the surface of ice sheets on Earth.
The space radar would take its cue from the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) instrument, which has probed the Red Planet’s underground for evidence of water from the European Space Agency’s (ESA) Mars Express spacecraft.
“I was having discussions with scientists from MARSIS, and I saw that what they had done could be applicable to Earth,” said Florence Heliere, the ESA scientist heading the concept study.
Mars Express wields a 131-foot (40-meter) long MARSIS antenna boom that dwarfs the spacecraft’s six-foot wide span, like a giant whiplash antenna on a tiny car. That main antenna pings the Martian surface with radar to try and detect underground water, but also receives a lot of unwanted clutter signals from the Martian surface and surrounding underground layers.
A second, smaller antenna detects only the scattered clutter signals that do not come from the target area directly below Mars Express. Scientists could theoretically subtract the clutter signals from the main antenna signal to get the true target reading, but the Mars Express team ultimately drew up a different solution that did not require the second antenna.
Still, the Mars dry run has inspired the early development of the Advanced Concept for Radar Sounder (ACRAS) that will set its initial sights on Earth’s Antarctic ice sheets.
“Antarctica is an area where the ice is cold and dry, so you can penetrate up to 3-4 kilometers (1.8-2.5 miles) within the ice,” Heliere told SPACE.com.
Continuous observation by ACRAS would help estimate the thickness of the Antarctic and other polar locations, as well as determine the three-dimensional internal structure of the ice sheets. Climate modelers could use data from the tool to get a better idea of how the ice sheets change over time as ice melts and reforms.