Curiosity eyes new ridge in exploration of the Red Planet
After nearly five years of its exploration of the Red Planet, the Mars Science Laboratory (MSL), more commonly known as the Curiosity rover, will begin its long-awaited study of a tantalizing ridge formation along a slope of Mount Sharp in the center of Gale Crater.
The iron-bearing ridge is one of four unique features in the lower elevations of Mount Sharp that drew the selection committee to choose this location for Curiosity’s mission destination.
The ridge that Curiosity is currently observing is thought to contain a high amount of iron oxide (Fe2O3), also known as hematite, which was located with the Mars Reconnaissance Orbiter (MRO) using its Compact Reconnaissance Imaging Spectrometer for Mars, or CRISM. Iron-oxide minerals form under wet conditions and can give researchers crucial information about the history and environment of ancient Mars.
Hematite can come in several colors, from gray to black, or reddish brown to red color, and is found and formed primarily in places where there has been still or standing water, or in or around mineral hot springs. CRISM also identified other water-related clay and sulfate mineral layers in the area near the ridge, which is now formally named “Vera Rubin Ridge” after astronomer Vera Cooper Rubin who passed away last year.
Vera Rubin Ridge is approximately eight stories tall and runs a length of about 4 miles (6.5 kilometers), and behind the ridge is the location of a trough where clay minerals are indicated.
“Curiosity is driving parallel to the ridge, below it, observing it from different angles as we work our way towards a safe route to the top of the ridge,” said Ashwin Vasavada, Project Scientist for Curiosity at the Jet Propulsion Laboratory (JPL) in Pasadena, California.
“In the first phase of the campaign, we’re studying the sedimentary structures in the wall,” said Abigail Fraeman, a member of the Curiosity science team who helped plan these observations.
The team also hopes to gather information on the boundary zone, an area between the material that makes up the ridge, and the “Murray formation” – which is the name of the geologic unit named after late planetary scientist Bruce Murray – that Curiosity has been studying since the end of 2014. The Murray formation, which is located in the low elevations of Mount Sharp, has provided evidence for ancient lakes.
One of the questions researchers want to answer is how and when the hematite in the Murray formation and that in the Vera Rubin Ridge formed. Currently, it is unknown whether they accumulated under similar conditions, but the hope is that the route up the slope of Mount Sharp to the top of the ridge will allow for a closer inspection and observation of the hematite iron-oxide rocks.
“We want to determine the relationship between the conditions that produced the hematite and the conditions under which the rock layers of the ridge were deposited,” Fraeman said. “Were they deposited by wind, or in a lake, or some other setting? Did the hematite form when the sediment accumulated, or later from fluids moving through the rock?”
A key question is whether the freshwater environment that deposited the layer that is the Murray formation were turning more acidic by the time the layers from the ridge were formed, as well as whether there may have been a gradient in oxidation which could have provided the necessary energy source needed for microbial life.
Curiosity has trekked through a variety of environments in its nearly five years on Mars, and in that time it has made some remarkable discoveries, including uncovering the presence of liquid water in Mars’ past as well as the finger prints of wind and water on the surface of the planet. There are challenges to achieving these goals, though.
The first of these challenges is in negotiating the terrain. In order to examine Vera Rubin Ridge, Curiosity will need to traverse the terrain which is composed heavily of boulders and sand especially near the base of the ridge. These conditions have the potential to be difficult, especially with the breakdown in the structure of several of Curiosity’s wheels.
The other significant challenge is that the rock sampling drill, which hasn’t been in service since December 2016, still will not be available, at least for the start of the campaign.
A mechanism on the drill that moves the drill bit forward and back failed late last year and hasn’t been able to be used since, although experts at JPL are trying to come up with alternate ways to move the drill bit as well as the feed mechanism.
“We’re investigating methods to drill without the stabilizers,” said Curiosity’s Deputy Project Manager Steve Lee of JPL. “Instead of using the feed mechanism to drive the bit into the rock, we may be able to use the motion of the arm to drive the bit into the rock.”
They are also looking at options for delivering the drilled powdered rock material into the instrument for analysis, which could include using the arm’s soil scoop as a delivery method.
Despite these challenges, the potential to add to the over all understanding of sand dunes and ripples, as well as gleaning a better understanding of Mars’ ancient history and habitability, makes for an irresistible goal.
A native of the Greater Los Angeles area, Ocean McIntyre's writing is focused primarily on science (STEM and STEAM) education and public outreach. McIntyre is a NASA/JPL Solar System Ambassador as well as holding memberships with The Planetary Society, Los Angeles Astronomical Society, and is a founding member of SafePlaceForSpace.org. McIntyre is currently studying astrophysics and planetary science with additional interests in astrobiology, cosmology and directed energy propulsion technology. With SpaceFlight Insider seeking to expand the amount of science articles it produces, McIntyre was a welcomed addition to our growing team.