Drag your mouse or move your phone to pan around
within this 360-degree view to explore the boxwork patterns on Mars that NASA’s
Curiosity is investigating for the first time. The rover captured the 291
images that make up this mosaic between May 15 and May 18.
Credit: NASA/JPL-Caltech/MSSS
The rover recently drilled a sample
from a new region with features that could reveal whether Mars’ subsurface once
provided an environment suitable for life.
New images from NASA’s Curiosity
Mars rover show the first close-up views of a region scientists had previously
observed only from orbit. The images and data being collected are already
raising new questions about how the Martian surface was changing billions of
years ago. The Red Planet once had rivers, lakes, and possibly an ocean.
Although scientists aren’t sure why, its water eventually dried up and the
planet transformed into the chilly desert it is today.
By the time Curiosity’s current
location formed, the long-lived lakes were gone in Gale Crater, the rover’s
landing area, but water was still percolating under the surface. The rover
found dramatic evidence of that groundwater when it encountered crisscrossing
low ridges, some just a few inches tall, arranged in what geologists call a
boxwork pattern. The bedrock below these ridges likely formed when groundwater
trickling through the rock left behind minerals that accumulated in those
cracks and fissures, hardening and becoming cementlike. Eons of sandblasting by
Martian wind wore away the rock but not the minerals, revealing networks of
resistant ridges within.
The ridges Curiosity has seen so
far look a bit like a crumbling curb. The boxwork patterns stretch across miles
of a layer on Mount Sharp, a 3-mile-tall (5-kilometer-tall) mountain whose
foothills the rover has been climbing since 2014. Intriguingly, boxwork
patterns haven’t been spotted anywhere else on the mountain, either by
Curiosity or orbiters passing overhead.
NASA’s Curiosity Mars rover viewed this low ridge,
which looks a bit like a crumbling curb, on May 16. Scientists think the
hardened edges of such ridges — part of the boxwork region the rover is
exploring — may have been formed by ancient groundwater.
NASA/JPL-Caltech/MSSS
“A big mystery is why the ridges were hardened into these big patterns and
why only here,” said Curiosity’s project scientist, Ashwin Vasavada of NASA’s
Jet Propulsion Laboratory in Southern California. “As we drive on, we’ll be
studying the ridges and mineral cements to make sure our idea of how they
formed is on target.”
Important to the boxwork patterns’
history is the part of the mountain where they’re found. Mount Sharp consists
of multiple layers, each of which formed during different eras of ancient
Martian climate. Curiosity essentially “time travels” as it ascends from the
oldest to youngest layers, searching for signs of water and environments that
could have supported ancient microbial life.
The rover is currently exploring a
layer with an abundance of salty minerals called magnesium sulfates, which form
as water dries up. Their presence here suggests this layer emerged as the
climate became drier. Remarkably, the boxwork patterns show that even in the
midst of this drying, water was still present underground, creating changes
seen today.
NASA’s Curiosity Mars rover captured this scene while
looking out across a region filled with boxwork patterns, low ridges that
scientists think could have been formed by groundwater billions of years ago.
NASA/JPL-Caltech/MSSS
Scientists hope to gain more insight into why the boxwork patterns formed
here, and Mars recently provided some unexpected clues. The bedrock between the
boxwork ridges has a different composition than other layers of Mount Sharp. It
also has lots of tiny fractures filled with white veins of calcium sulfate,
another salty mineral left behind as groundwater trickles through rock cracks.
Similar veins were plentiful on lower layers of the mountain, including one
enriched with clays, but had not been spotted in the sulfate layer until now.
“That’s really surprising,” said
Curiosity’s deputy project scientist, Abigail Fraeman of JPL. “These calcium
sulfate veins used to be everywhere, but they more or less disappeared as we
climbed higher up Mount Sharp. The team is excited to figure out why they’ve
returned now.”
New Terrain,
New Findings
On June 8, Curiosity set out to learn about the unique composition of the bedrock in
this area, using the drill on the end of its robotic arm to snag a sample of a
rock nicknamed “Altadena.” The rover then dropped the pulverized sample into
instruments within its body for more detailed analysis.
Drilling additional samples from
more distant boxwork patterns, where the mineral ridges are much larger, will
help the mission make sense of what they find. The team will also search
for organic molecules and other evidence of an ancient habitable environment preserved in
the cemented ridges.
As Curiosity continues to explore,
it will be leaving a new assortment of nicknames behind, as well. To keep track of features on the planet, the mission
applies nicknames to each spot the rover studies, from hills it views with its
cameras to specific calcium sulfate veins it zaps with its laser. (Official
names, such as Aeolis Mons — otherwise known as Mount Sharp — are approved by
the International Astronomical Union.)
The previous names were selected
from local sites in Southern California, where JPL is based. The Altadena
sample, for instance, bears the name of a community near JPL that was severely
burned during January’s Eaton Canyon fire. Now on a new part of their Martian map, the team is selecting names from
around Bolivia’s Salar de Uyuni, Earth’s largest salt flat. This exceptionally
dry terrain crosses into Chile’s Atacama Desert, and astrobiologists study both
the salt flat and the surrounding desert because of their similarity to Mars’
extreme dryness.
More About
Curiosity
Curiosity was built by NASA’s Jet
Propulsion Laboratory, which is managed by Caltech in Pasadena, California. JPL
leads the mission on behalf of NASA’s Science Mission Directorate in Washington
as part of NASA’s Mars Exploration Program portfolio.
For more about Curiosity, visit: science.nasa.gov/mission/msl-curiosity
Source: NASA’s Curiosity Mars Rover Starts Unpacking Boxwork Formations - NASA
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