ASU professor Jack Farmer not only teaches astrobiology, but he is also involved with the NASA program to analyze the data sent back by the Curiosity Mars rover as part of a larger effort to search for signs of life beyond Earth. Last month, Farmer co-authored two papers published in the journal Science about the findings of a team of chemical and mineralogy scientists. The question of extraterrestrial life is one that is fundamental to humanity, Farmer said.
“Are we alone?” he said. “Everybody thinks about that ... you look up at the sky and think, ‘Am I by myself out here?’ They’ve been asking that since the beginning of humanity.”
NASA's Mars Science Laboratory mission is trying to answer this question by looking for life on Mars. Its platform is the Curiosity rover, which landed on the Gale Crater on Aug. 5 of last year.
This landing site was selected because of its interesting geology, which includes a thick section of layered sedimentary rocks.
Farmer is part of a team involved with the rover’s chemistry and mineralogy experiment, also known as CheMin. Curiosity’s CheMin instruments use X-rays to interrogate powdered samples of rock and soils to reveal what they contain.
These minerals carry information about the geological processes that formed the samples, giving information about the early history of Mars. The team then uses this history to tell if Mars could have ever supported life.
“Life needs liquid water, energy sources and carbon compounds that can be turned into something like microbes,” Farmer said. "CheMin is trying to find minerals that tell us that there were environments present that could have sustained life."
The CheMin X-ray Diffraction experiment marks the first time X-rays have been used to learn what minerals are present on the surface of another planet.
The first results from CheMin have come during the 100th anniversary of X-ray diffraction's first use as a method, an exciting milestone for the team and all who routinely use this method to analyze the mineral make-up of samples.
“One hundred years after the process was invented we got the first X-ray Diffraction patterns back from Mars," Farmer said.
The centennial was yet another reason to celebrate, after a flawless landing and a year of nearly perfect operations, he said.
After the rover landed, Farmer said it underwent many exercises to ensure it was fully functional. Then Curiosity began looking for finely powdered material that could be used for samples in its two primary on-board testing instruments, CheMin, which uses the X-ray Diffraction, and Sample Analysis at Mars, which looks for carbon compounds.
Soon, the rover found what it needed.
“We found wind-rippled sands, in a wind-shadowed area behind a pile of rocks in a beautiful symmetrical ripple,” Farmer said. “We processed many samples, put it through a sieve and found the right amount of finely powdered sand, and we got the results.”
The CheMin analysis reported that the ripple contained a compound of rock similar to basalt, the most common rock on Earth's surface. This came as no surprise to the team, Farmer said. However, it also revealed several other minerals that the team was not expecting.
“What was a surprise were the other components, such as a material that showed that water existed that created a crusted surface, and in addition, almost half of the sample was made of amorphous material, similar to glass, lacking an internal structure, essentially crushed glass,” he said.
Though scientists had previously suspected that the glass-like material was on Mars, Farmer said his team was amazed by its abundance, as it made up nearly half of this specific sample.
There are many speculations about the origin of this material, and Farmer said the team is still working on this aspect.
The team plans to continue to collect and analyze samples on Mars for as long as the rover continues to function, and it plans to focus on the multi-layered geology of Mount Sharp to continue to reveal the history of the red planet. Mount Sharp's makeup is three times thicker than the geologic sequence of the Grand Canyon.
In addition to his involvement with NASA, Farmer also teaches geology and astrobiology in the School of Earth and Science Exploration at ASU, using his real-world experiences to give his students additional insight into the field.
“During the nominal (first ninety days of) the mission, I offered a course by video to focus on the mission, review the aspects of the rover, its instruments,” he said. “I brought the students out to the jet propulsion lab as a field trip, including the test bed rover which is a twin of Curiosity.”
Kristen Bennett, a planetary science graduate student, took this video course, called Advanced Field Geology. She attended a video teleconference with Farmer every week, who explained the events of the mission in real time and often brought experts to lecture the students about individual instruments on the rover.
“Every single thing we wanted to know, every aspect about the rover we got to see and talk to the experts with the help of Professor Farmer,” Bennett said.
Nathan Williams, a geology and planetary science graduate student, took a class from Farmer and said the professor's passion and experience are inspiring every day.
"I really appreciate and enjoy Jack's commitment to education and inspiring people to think about our own origins and understanding the context of our existence from a planetary and cosmic perspective, and his application of testable hypotheses and experiments to address them," Williams said in an email.
Geological sciences graduate student Michael Veto also took this course with Bennett.
“He’s exposing us to the real thing,” he said. “The real people, the real hardware, the real places.”
Veto said Farmer’s passion for space exploration is apparent in everything he does, including celebrating Halloween. Last year, he dressed as a NASA scientist while taking his daughter trick-or-treating.
Farmer’s involvement with the Curiosity project made his class experience realistic and unforgettable, Veto said.
“It’s one thing to read about the space program in a book, and it’s one thing to have someone teach you from a book, but to have someone intimately involved with these projects, who can share their real-world testimonials and experiences, that’s what inspires you to learn the material,” he said.
Reach the reporter at elmahone@asu.edu or follow her on Twitter @mahoneysthename
