3. Solving the Methane Mystery
Several research groups over the past six years have reported finding methane in the atmosphere on Mars. In Earth, about 98 percent of the atmospheric methane comes from biological sources such as humans and cows.
"To put it humorously," Veto says, "The estimation is there are two cows on Mars gauging by the methane production."
Because methane has a short half-life (breaks down quickly once released into the air), scientists want to find the source of the gas on the planet. Even if the methane on Mars comes from a non-biological source, the presence of the gas indicates the planet is definitely still alive -- at least in a geological sense.
2. The Gale Crater: an anomaly
Veto remembers during his first class at Arizona State, when scientists were still debating the ideal landing spot for the Curiosity rover. He says, they probably chose the Gale Crater because of its uniqueness within the geological context of the planet. In the center of the crater sits a large mound, known as Mount Sharp. The mountain rises about three miles from the surface and is taller than one of the sides of the crater it sits in.
Using data gathered from orbiting spacecraft, they have already determined many different minerals comprise the layers of Mount Sharp. Scientists hope to use the types of minerals as a "history book" of the Martian climate in the past. Veto says some hypothesize that the uppermost layers could be made up of snow pack or dust. Like Earth, the planet Mars goes through ice ages and he says our ancestors could have looked up to see a white planet, instead of the red planet we know today.
But why do scientists care about ice ages on Mars? Veto says a better understanding of climate cycles on Mars, a planet untouched by humans, could help us understand and measure the effects we've had on our own planet.