The smooth mounds of cinder cones filled the horizon as a group of three students set off up a slope near SP Crater last week. They were equipped with a GPS, a ghostbusters-esque device to measure the strength of the Earth’s magnetic field and a computer-and-sled contraption to emit and measure ground penetrating radar.
The 5-kilometer route they followed was the same one taken by a NASA rover six years ago as astronauts tested how it could traverse this type of terrain and be used for field geology work on other planetary bodies.
This time around, a research team from Northern Arizona University, the University of Maryland and NASA is instead studying what’s below the surface in this section of the San Francisco Volcanic Field.
That sort of subsurface data collection wasn’t done in the 2010 NASA mission but it is an important part of exploring anything from the moon to an asteroid to another planet, said Nicholas Schmerr, an assistant professor of geology at the University of Maryland.
Over three years, Schmerr said this project will add another layer of information to astronauts' past work in this area.
“Basically we’re trying to recreate what (the astronauts) would have seen if they would have been dragging that system behind them or carrying it with them,” Schmerr said.
The area around SP Crater is ideal for geological and geophysical field tests because the cinder cones and solidified lava flows are similar to what astronauts might see on other planetary bodies, he said.
Through several different testing techniques, the researchers are examining how lava flows are related to the underlying rocks, estimating the relative timing of ancient volcanic eruptions and tracking the area’s seismicity. They’re also looking at how different equipment functions in an environment like the cinder cones.
This year, the team is retracing the routes taken by NASA rovers while next year the goal will be to find the best places and ways to collect the data to find areas for improvement, Schmerr said.
While one group of students set off to retrace the rover’s route, another team stationed themselves along a 120-meter cable stretched across the ground. In a procedure called active source seismology, one person swings a 10-pound sledgehammer down on an aluminum plate placed on the ground. The plate is hooked up to the cable lined with geophones that pick up seismic waves as they travel through different rock and sediment layers. As they travel through the ground, the waves bend differently depending on the material, which is what can be measured to distinguish different layers, Schmerr said.
The information that is gathered in these experiments will be used to write academic papers and create recommendations for how engineers can better design instruments and equipment to be used by astronauts collecting geophysical data, Schmerr said.
Their techniques and processes also will be relayed back to NASA directly thanks to astronaut Don Pettit, who shadowed the fieldwork.
Pettit is a veteran of three different space missions who works at the Johnson Space Center. He was there taking “scads of pictures” and learning how geologists collect this type of data, he said.
“We’ll have to learn all we can from these guys and gals then blast off into space and end up on another planet and collect as much good data as we can,” Pettit said. “It’s all part of what makes an integrated scientific exploration when you are going to a place you know very little about.”