Curiosity Will Carry an Instrument for Underground Research

Mission controllers at the NASA Jet Propulsion Laboratory (JPL), in Pasadena, California, say that the Mars Science Laboratory (MSL) rover Curiosity will have the ability to look for signs of water trapped in minerals underneath the surface of the Red Planet.

The Dynamic Albedo of Neutrons (DAN) instrument will be responsible for this capability, the team reports. The tool is capable of conducting investigations up to a depth of about 50 centimeters (20 inches), and is extremely sensitive.

If the shallow underground minerals that Curiosity will drive past hold any traces of water, DAN will find them. Such a discovery would be essential for determining if liquid water actually existed at some point on the planet's surface and, if so, when.

Thus far, several data sources – including rovers, landers, orbiters, telescopes and computer models – have indicated that Mars had a wet climate billions of years ago. River channels, deltas and lake beds are evidence of liquid water flow.

“If we conclude that there is something unusual in the subsurface at a particular spot, we could suggest more analysis of the spot using the capabilities of other instruments,” explains Igor Mitrofanov, who is the principal investigator for DAN. He is based at the Space Research Institute, in Russia.

The expert says that the true strength of Curiosity is not one of its instruments, but rather the entire suite. The 1-ton rover, which is the size of a Mini Cooper, carries a total of 10 instruments, which are capable of working together to pierce whatever mystery Mars has to throw at them.

The way DAN works is very complex, says the Russian team. The instrument is responsible for injecting high-energy neutrons into the Martian underground, and then detecting how these elementary particles bound off atomic nuclei underneath.

For each possible type of pattern DAN may detect, experts already have a category of chemicals or materials associated with the numbers. For instance, hydrogen can be detected because its atoms reflect neutrons in a very specific manner.

If oxygen and hydrogen are found together, then investigators would have essentially found water underneath the Martian surface. “You can think of DAN as a reconnaissance instrument,” Mitrofanov explains.

At this point, the MSL is scheduled to take off between November 25 and December 12, so that it can reach Mars by August 2012. If this window of opportunity is lost, then NASA will have to wait nearly two years before the spacecraft can be launched.