|Hydrated Mars of Old|
Anyone ever wonder how they search for water in space? With NASA’s newest Mars rover - Curiosity - due to land on Mars on August 6 this is a timely topic as this rover will be looking for water.
It turns out there are actually a number of ways to look for or detect water on moons and planets we have begun to explore. These include spectroscopic measurements, radar, regular old photography, the presence of minerals known to retain water, direct observation and the latest way going to be used by Curiosity – employing the dynamic albedo of neutrons.
This approach will shoot millions of neutrons into the soil in microbursts of energy. The neutrally-charged neutrons when they hit hydrogen atoms will slow to a near stop because of their similar sizes, and by catching the returning signals the presence and amount of water can be determined. The tests are also designed to learn more about the water cycle of Mars, it’s near ground climate and whether seasonal soil moisture patterns exist – all in about 20 minutes of pulsing neutrons. This had better work well, because where they intend to land, in the vicinity of the Gale Crater, there are only clays and sulphates - hydrated minerals.
I was surprised to learn that this is not the first foray to Mars looking for water. It began with the Mariner 9 mission in 1971, and has since then included the Viking program, the Mars Global surveyor, Mars Pathfinder, Mars Odyssey, Phoenix, the Mars Rovers, the Mars Reconnaissance Orbiter, Mars Express and the Mars Opportunity Rover. You’d think we’d already have had a pipeline headed toward California by now.