Archive for the ‘Mars’ Tag
A new tool for Mars explorers
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Sand ripples and a pavement of outcrop rock on Mars. Image Credit: NASA/JPL-Caltech.
Landers and rovers sent to Mars carry a wide range of scientific instruments for studying their environment on the planet’s surface. One can imagine them scratching at the ground beneath their feet, motors whirring and clicking to prepare and analyse samples. Cameras pan around and take in the scene, while lasers shoot into the sky to study the weather of the red planet. Now, in the search for groundwater on Mars, there is a new tool that future landers may come equipped with, allowing them to see deeper into the rocky surface than ever before.
Ground penetrating radar has the advantage that it can operate remotely from aboard an orbiting satellite, which means the whole planet can be mapped for signs of water at or below the surface, but it just can’t see far enough, particularly through rock. This is where a new electromagnetic sounding device may provide a solution.
Researchers in the Department of Space Studies at Southwest Research Institute, have built and tested the Mars Time Domain Electromagnetic Sounder (MTDEM)†. The working device would weigh in at less than 6 kg and be operated from a robotic lander. Using compressed gas cannisters, it deploys a loop antenna by firing two projectiles, consisting of spooled up wire, as far out as 200 m.
The triangular antenna induces electrical currents in the ground which are then detected at the surface. This technique should be able sense the characteristically high electrical conductivity of any groundwater in the region, to depths far greater than can be achieved with ground penetrating radar. The researchers claim that such an instrument should be able to detect water as far down as 5 km.
It is believed that water helped shape the geology of Mars in the distant past, and it is speculated that large quantities of that water may still exist deep beneath the surface of the planet. If discovered, it will explain a lot about Mars today and in the past, but it will also bring questions, such as can we use it for human habitation of Mars and is there anything already living off of it?
† Grimm, R. E., et al., A time-domain electromagnetic sounder for detection and characterization of groundwater on Mars. Planet. Space Sci. (2009), doi: 10.1016/j.pss.2009.05.003
