The Curiosity rover may have landed on the Red Planet months ago, but the work of the researchers on the science team — including Ralph Milliken MS ’03 PhD ’06, assistant professor of geological sciences — is far from over.
The NASA Mars Science Laboratory Rover mission aims to probe at the mystery of whether the planet could have once supported microbial life. The rover was launched in November 2011 and landed on Mars last August.
Curiosity is currently located in Yellowknife Bay, an area of flat-lying bedrock within a wide, shallow depression, according to a NASA press release. There, the team is preparing to take the first drill sample of Martian rock, Milliken said.
“Basically what we’ll do is take the rock powder and measure the actual minerals that make it up,” he said. This will yield results that are significantly different from previous observations, which focused primarily on chemicals and elements in the rocks. From the sample analysis, Milliken said he hopes to determine if the mineral composition is indicative of “interactions with water, volcanic processes and things of that nature.”
The research team faces unique technical challenges due to the complexity and distance of the mission, Milliken said. The Martian material should be soft enough to not break the drill bit, but the surrounding area must provide Curiosity’s wheels with sufficiently solid footing for the job, as the process also requires extreme force.
“We don’t want to damage the drill, but we also don’t want it to move while it’s drilling,” Milliken said. “The tricky aspect is trying to find some middle ground that’s safe and properly constrained. It takes a lot of care and patience to make sure it’s done properly.”
Research has revealed there was once water on Mars, Milliken said. “But now what we want to understand is the interaction of that water on the surface and subsurface of the planet. Were these rocks that we’re drilling into in contact with water? If so, for how long, and to what capacity, and how has this changed over time?”
The mission is grappling with such questions that seek to find traces of organic material that will answer the cosmic uncertainty of Martian life.
Knowledge of life on Earth provides a foundation to guide the space exploration, Milliken said. “From our terrestrial experience, we know which minerals and environments are indicative of water and what places to look in.”
Milliken said after Curiosity’s drilling in Yellowknife Bay, the mission will progress onto its ultimate goal — investigating Mount Sharp, a 5.5-kilometer mountain on Mars. First, the team must focus on reaching the base of the mountain, he said. “From there, we can uncover layers of Martian history.”
One of the major discoveries revealed by Curiosity’s probing is the diversity of geology on Mars’ surface. “One of the first big things we’ve found are conglomerates, which are rounded pebbles sort of cemented together,” Milliken said. These are indicative of flowing water, perhaps a shallow stream, which once existed in the crater and gave these rocks their appearance, he said. “Other rocks we’ve found look much different, with finer grain and light-toned fractures and veins filled with minerals, and this points to a whole other interaction.” Even from the small sampling of rocks the rover has revealed, the mission is beginning to uncover a complex and diverse story, he added.
“What’s really exciting about the rover is that it’s by far the closest to putting a geologist on Mars,” said Timothy Herbert, professor and chair of the geological sciences department. “This is a place with a great geological record where we can take samples in order to make more sense of the planet. Whatever the rover finds will really transform a lot of theories we have at this point.”
Milliken said the rover’s capabilities speak to the advanced technology of this age.
“The rover acts as our eyes, and through it, we can answer increasingly sophisticated questions about the geology of Mars and how it fits into the evolution of the solar system from billions of years ago.”
ADVERTISEMENT
