Water found on Mars, not just in ice caps
The Curiosity rover discovered water in soil samples on Mars, according to NASA .
Tonya Triplet, a senior lecturer in the physics department, said the discovery is both exciting and disappointing.
“We have many reasons to believe that water might be the best indicator that life could exist on a world,” Triplet said.
Searching for water is most often the primary focus of space explorations because life has a connection with water.
“Searching for water has the goal of almost every exploration ever sent, particularly to Mars, but everywhere else as well,” she said.
However, it is important to remember that the presence of water does not necessarily mean life exists, Triplet said.
“We seek water for the possibility for the existence of life as opposed to evidence that life exists,” she said.
When searching for an environment that could possibly support life, the first thing to look for is surface liquid water similar to what we have on Earth like rivers, lakes and oceans. Nothing like this has been discovered on Mars as of yet, Triplet said.
“It’s not because it’s too cold,” she said. “It’s because the air pressure is too low. You can’t have surface liquid water.”
The second factor researchers search for is subsurface liquid water, similar to Earth’s aquifers. The surface of Mars has features that indicate a good possibility of subsurface water, Triplet said.
One prime example of this is the existence of ‘squishy craters,’ Triplet said. When a projectile strikes a surface where water exists, the material ejected exhibits itself as mud and a squishy crater is the result. The question is then what state the subsurface water was in when it was hit.
“If it was frozen like permafrost, it is much less probably to support life than liquid water in an aquifer of some kind,” Triplet said.
The first photo evidence that subsurface water exists on Mars was discovered by accident in 2005 when the Mars Global Surveyor outlived its expected lifespan and started over its programming sequence, Triplet said.
“The repeat photo showed water had flowed in a crater in the time between photos,” she said.
The latest water discovery by the Curiosity rover was different than any of the previous findings in that it is not liquid water.
“This water is chemically bound in structures within the soil,” Triplet said.
Triplet said what most people think of when they hear of water in soil is mud. This does not accurately describe the discovery made on Mars.
“We are not talking about moist soil,” she said. “Instead what we are talking about is water that is bound in the chemistry of the soil.”
Triplet said the hydrates in the soil may or may not matter, depending on what a specific individual deems to be important and what they are looking for.
When applied to the search for water to mean a possibility for life, this discovery may be a setback.
“Water chemically bound into structures can be released with extraordinary amounts of energy, usually in the form of heat,” Triplet said. “What living thing has enough energy to obtain its water through those mechanisms?”
The good news is there is a possibility for water to be evaporated out of the soil for use by human exploration of Mars in the future, Triplet said.
“This is where all the excitement about this discovery comes from,” she said. “The challenge now becomes supplying the energy required to accomplish this. It’s not going to be free.”
The discrepancy between these two goals is the basis for the controversy over the bound water in the soil.
“It is good for future explorers, but it is really bad for finding life,” she said.
Although the technology exists to do it, Triplet believes human Martian exploration is still a long way out, primarily because of what most people value as important.
“We are scientifically able to do this,” she said. “What we don’t have is a commitment to it.”
This kind of firm commitment was demonstrated in the 1960s when man first walked on the moon, Triplet said.
“When President Kennedy made is speech, people rallied around it,” she said.
At the present, people are very focused on things closer to home such as Social Security, Medicare and healthcare, Triplet said.
“We are choosing to spend our money on very human things,” she said. “I don’t question their viability, I’m just noting that we can’t do both.”
-ashlyn.tucker@aggiemail.usu.edu