Scientists have evidence that the 3-mile mountain range in the middle of the Mars Crater can be mostly made of dust and sand.
To find out about this amazing conclusion, researchers MacGyvered created NASA's Rover Curiosity navigation tool and turned it into a scientific tool.
The idea of Rover's inertial measurement unit repurposing comes from Kevin Lewis.
"It didn't satisfy me that we didn't have a surface gravimeter on Mars," says Lizis, a member of the scientific science team, and an associate professor of land and planet science at Johns Hopkins University.
You can learn a lot about the geology of the planet by measuring its fine gravity changes. High density stones give a stronger signal for low density.
But for gravity measurements, you usually need a tool called a gravimeter.
One day Lewis started thinking about something that regularly appeared in the rover's daily schedule.
"It turns out that we're rover every day, there's a little rover activity called SAPP-RIMU data activity," Lewis says.
SAPP stands for "surface attitude and indication". SAPP-RIMU data activity is something engineer to determine the exact orientation on the planet's surface.
There are three devices inside the RIMU to measure acceleration – similar to accelerometers on a smartphone that measure phone movements.
Kevin Lewis was a kind of epiphany.
"We don't have a gravimeter on Mars surface, but we have accelerometers," he says, "and gravity is just an acceleration."
You should not think about gravity in the way, but you can, and scientists do it.
So, with the help of NASA's Jet Propulsion Laboratory engineers, Stephen Peters and Kurt Gonter, he was able to customize the way RIMU processed the data; who gave Lewis his gravimeter.
He knew what he wanted to do with it: Try to figure out how a 15,000-foot-long hill in which crater curiosity unloads could form in the middle of the Gale Crater.
This is a question that many scientists have surprised.
"There have been two distinct schools of thought," says Mackenzie Day, assistant professor at the Department of Earth, Planets and Space Science at UCLA.
"Craters are fundamentally large holes in the ground," said Day. "So they are a very good place to accumulate things: accumulate deposits, accumulate dust and sand."
One of the questions that the scientists have been surprised to say is: Did the Gale crater once fill with a sediment circle, and then most of this material disappeared, leaving behind what is now called the Sharp Mountain?
"Or," Day says, "is Mount Sharp something that has evolved in the middle of the crater – a sort of gorgeous material in the center of the crater – from the winds that fall off the edge of the crater?
Would sand and dust blowing really make up a 3 mile mountain?
Perhaps, although Kevin Lewis admits that this is against our expectations.
"We usually don't see mountains as a haystack on Earth," Lewis says.
If the haystack model is correct, the stone at the base of Sharp Hill would not be very dense.
"What we found in this study is stones are surprisingly low density," Lewis says.
That is why haystack theory can be correct as he and his colleagues report in the magazine Science.
Lewis says he plans to continue collecting data from his MacGyvered tool to find out if the initial results hold.