NASA's top scientists - including a Texas A and M University researcher - hope to find out how Mars' climate has evolved over billions of years, and answers could come soon in the mission involving Curiosity, a Volkswagen-sized rover that is headed toward the Red Planet and will land in early August. It was launched Nov. 26, 2011, and is traveling at 13,000 miles per hour.

Once there, it could answer many questions scientists have had for decades, including some involving the possibility of life on the planet, says Mark Lemmon, an atmospheric sciences professor at Texas A and M who will serve as one of Curiosity's camera operators.

The mission involves Curiosity landing near the Martian equator and inside Gale Crater on Aug. 6, and for the next two years, it will investigate how climate change over billions of years has affected Mars and examine the nearby clay layers from an environmental aspect. It will also try to determine whether Mars has ever had conditions favorable for life, even in the smallest microbial forms.

"Curiosity will have the ability to drive scientific instruments, including a camera on a robotic arm, and also a new twist this time - high-definition video cameras," Lemmon explains.

"The cameras have the ability to take landscape images as well as some very closeup images, sort of similar to what you might see by looking through a magnifying glass. We hope to have some images of Mars we've never come close to getting in previous missions."

Curiosity resembles a sort of high-tech dune buggy. It stands almost eight feet high, weighs about 1,800 pounds and employs a nuclear-powered battery to run its many scientific tests.

Lemmon says the Gale Crater was specifically selected for several reasons. It's beside a high mountain ("it's really huge, about the size of Mt. Rainier in Washington State, but made of sedimentary rock"), and the area around the crater shows near-certain proof that water was in the area at some time.

"We know water was there, and possibly in large amounts, maybe sometimes as large acid-filled lakes," he notes. "So if water was there and it's dry now, what happened? What changes occurred in Mars' climate history that made it go from wet to dry over time? We hope to find out."

Lemmon is no stranger to NASA missions. He's participated on numerous such explorations in the past, including the Spirit and Opportunity Mars rovers that landed eight years ago, Phoenix, Cassini and other others. But this one could be the most exciting of all, he points out.

"It's always fun to go back to Mars," he says of the Curiosity mission. "We know so much more about Mars than we did just a few years ago. We took hundreds of thousands of images using the cameras on Spirit and Opportunity, and Curiosity will take just as many or more.

"What they show will let us see Mars in a completely different light than ever before."