Our curiosity about life on Mars

by Mark Ollig

John Grotzinger, chief scientist of NASA’s Mars Curiosity mission, was asked if life could exist on Mars.

Those of us seated in the Fitzgerald Theater, in St. Paul, anxiously awaited his answer.

Grotzinger paused, and then began by saying the drilled rock samples Curiosity recently obtained had a grayish-green color which excited the scientists.

Using a northern Minnesota comparison, he said the Mesabi iron ranges are made out of the type of iron that is red. Grayish rocks can also be found there.

When collecting the gray rocks, sometimes you find materials representing former organic micro-organisms that lived on Earth around 1.8 billion years ago, when these northern Minnesota rocks were being formed, Grotzinger indicated.

Hopefully, Curiosity will be able to take samples of gray Martian rocks, and look for some organic compounds, he proposed.

By studying the rocks on Mars, which have not been affected by the tectonic plate shifting as the ones here on Earth have been, Grotzinger believes we will learn more about how life got started on our planet.

Grotzinger suggests the Martian rocks may be able to “fill in the gaps” of what is missing here on Earth, and help us to understand Earth’s past.

He compared the method Curiosity uses to test Martian soil and rock samples to how a cake is made in an oven. In this case, the Martian “cake” is cooked in Curiosity’s oven at around 2,732 degrees Fahrenheit.

The heated vapor compounds given off from the Martian samples are then subjected to several scientific testing procedures.

Millions of years into the future, how will our own human existence here on Earth be proven, if some extraterrestrial intelligence would happen to visit our planet, as we are now doing on Mars?

According to Grotzinger, we will leave behind proof of our physical existence with the cholesterol animal cell membrane molecules each of us have.

Tom Weber, of Minnesota Public Radio, asked, “How many Curiosity rovers exist in the universe?”

“Well, there’s sort of two-and-a-half,” replied Grotzinger.

“That is such a NASA answer,” Weber jokingly said.

Those of us in the audience, along with Grotzinger, laughed.

Grotzinger said, “There’s the Curiosity rover on Mars, and the nearly identical rover located here on Earth called the VSTB (vehicle system test bed), which is used to check out the capability of the science instruments, using the rover arm, using the mast [camera] taking pictures. There is another rover used as a field test model they drive around at a facility at JPL called the Mars Yard. This rover drives over simulated surface conditions found on Mars to test out all the mechanical capabilities of the rover. This field model rover has none of the computers.”

This rover has “all heart and no brain . . . we call it the Scarecrow,” Grotzinger quipped.

The Curiosity rover on Mars is fitted with two built-in computers.

March 12, NASA headquarters held a news conference announcing the results from the first rock drilling experiment on Mars.

At that conference, Grotzinger, along with other scientists, made public the discovery of geological proof of an earlier existence of water on Mars.

Grotzinger said the area where Curiosity drilled into the rock looked like a “lake bed” filled with sediment derived by streams, but it is not known how long it existed. He does say they feel it was wet for reasonably long enough periods for chemical reactions to occur.

One question I liked asked of the scientists by the press attending the conference was, “How do you feel?”

Michael Meyer, NASA’s Mars Exploration Program lead scientist, began by explaining the concern scientists had, wondering if they had picked the right spot for the Curiosity rover to land (Gale Crater).

“You can imagine the relief landing there, and then, almost right off the bat, we do find evidence of water, and we see an ancient river bed. We are now finding an environment in the near subsurface, you know, not too far beneath the oxide layer, of finding a sort of a neutral rock, all the things that we were really hoping for, to find a place that could have been inhabitable in its past. So, as far as I’m concerned this is fantastic, all the rest is gravy in terms of how the rover is going to go about looking around this area . . .because it definitely was . . . all the indications of being an inhabitable environment at one point in time,” he surmised.

Asked about how well the Curiosity rover handles on Mars, Grotzinger said, “It’s a capable vehicle; it does as well as a four-wheel-drive car.”

He also joked how Curiosity’s robotic arm can stretch out long enough to dunk a basketball.

When asked if Grotzinger would rather have humans than robots on Mars, he replied having humans on Mars would be better than robots. What would take two years to be accomplished by robots, would just take two days using human astronauts, he commented.

When asked what one moment of the Curiosity mission stands out for him, Grotzinger answered, “The night you land, and you realize the moment when they hand the keys over to you. It [Curiosity rover] is a priceless national asset. The rover might be driving around there in 10 to 20 years.”

The next Mars rover mission will be launched in 2020.

Grotzinger said this will be a “sample return mission” with one rover gathering Martian rocks. The rocks collected would be returned to Earth in a future rover mission.

The homepage for NASA’s Curiosity rover is http://mars.jpl.nasa.gov/msl.

To listen to the Minnesota Public Radio-recorded audio from the Science Night Minnesota Mission to Mars at the Fitzgerald Theater, go to http://tinyurl.com/p49qff2.

Follow the Curiosity rover and its mission on Facebook and Twitter at:http://www.facebook.com/marscuriosity and http://www.twitter.com/marscuriosity.