Mars rover Curiosity makes first gravity-measuring traverse …
A intelligent use of non-science engineering knowledge from NASA’s Mars rover Curiosity has let a group of researchers, together with an Arizona State College graduate scholar, measure the density of rock layers in 96-mile-wide Gale Crater.
The findings, to be revealed February 1, 2019, within the journal Science, present that the layers are extra porous than scientists had suspected. The invention additionally provides scientists a novel method to make use of sooner or later because the rover continues its trek throughout the crater and up Mount Sharp, a three-mile-high mountain in its middle.
“What we were able to do is measure the bulk density of the material in Gale Crater,” says Travis Gabriel, a graduate scholar in ASU’s College of Earth and House Exploration. He labored on computing what the grain density must be for the rocks and historic lakebed sediments the rover has been driving over.
“Working from the rocks’ mineral abundances as determined by the Chemistry and Mineralogy instrument, we estimated a grain density of 2810 kilograms per cubic meter,” he says. “However the bulk density that came out of our study is a lot less — 1680 kilograms per cubic meter.”
The a lot decrease determine reveals that the rocks have a lowered density most certainly ensuing from the rocks being extra porous. This implies the rocks have been compressed lower than scientists have thought.
Like a Smartphone, however higher
The engineering sensors used within the research have been accelerometers and gyroscopes, very similar to these present in each smartphone. In a telephone, these decide its orientation and movement. Curiosity’s sensors do the identical, however with a lot higher precision, serving to engineers and mission controllers navigate the rover throughout the martian floor.
However whereas the rover is standing nonetheless, the accelerometers additionally measure the native drive of gravity at that spot on Mars.
The group took the engineering knowledge from the primary 5 years of the mission — Curiosity landed in 2012 — and used it to measure the gravitational tug of Mars at greater than 700 factors alongside the rover’s observe. As Curiosity has been ascending Mount Sharp, the mountain started to tug on it, as nicely — however not as a lot as scientists anticipated.
“The lower levels of Mount Sharp are surprisingly porous,” says lead creator Kevin Lewis of Johns Hopkins College. “We know the bottom layers of the mountain were buried over time. That compacts them, making them denser. But this finding suggests they weren’t buried by as much material as we thought.”
Making Mount Sharp
Planetary scientists have lengthy debated the origin of Mount Sharp. Mars craters the dimensions of Gale have central peaks raised by the shock of the affect that made the crater. This might account for a part of the mound’s peak. However the higher layers of the mound look like manufactured from wind-scoured sediments extra simply eroded than rock.
Did these sediments as soon as fill your entire bowl of Gale Crater? In that case, they may have weighed closely on the supplies on the base, compacting them.
However the brand new findings recommend Mount Sharp’s decrease layers have been compacted by solely a half-mile to a mile (1 to 2 kilometers) of fabric — a lot lower than if the crater had been utterly stuffed.
“There are still many questions about how Mount Sharp developed, but this paper adds an important piece to the puzzle,” mentioned Ashwin Vasavada, Curiosity’s challenge scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California, which manages the mission. “I’m thrilled that creative scientists and engineers are still finding innovative ways to make new scientific discoveries with the rover.”
Gabriel provides, “This is a testament to the utility of having a diverse set of techniques with the Curiosity rover, and we’re excited to see what the upper layers of Mount Sharp have in store.”