NASA's Mars Curiosity Rover captures a selfie to
mark a full Martian year -- 687 Earth days -- spent exploring the Red
Planet.
Image Credit:
NASA/JPL-Caltech/MSSS
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NASA’s Mars Curiosity rover will complete a Martian year -- 687 Earth days --
on June 24, having accomplished the mission's main goal of determining whether
Mars once offered environmental conditions favorable for microbial life.
One of Curiosity's first major findings after landing on the Red Planet in
August 2012 was an ancient riverbed at its landing site. Nearby, at an area
known as Yellowknife Bay, the mission met its main goal of determining whether
the Martian Gale Crater ever was habitable for simple life forms. The answer, a
historic "yes," came from two mudstone slabs that the rover sampled with its
drill. Analysis of these samples revealed the site was once a lakebed with mild
water, the essential elemental ingredients for life, and a type of chemical
energy source used by some microbes on Earth. If Mars had living organisms, this
would have been a good home for them.
Curiosity Rover Report: Mars rover completes its
first Martian year.
Image Credit:
NASA/JPL
Other important findings during the first Martian year include:
-- Assessing natural radiation levels both during the flight to Mars and on
the Martian surface provides guidance for designing the protection needed for
human missions to Mars.
-- Measurements of heavy-versus-light variants of elements in the Martian
atmosphere indicate that much of Mars' early atmosphere disappeared by processes
favoring loss of lighter atoms, such as from the top of the atmosphere. Other
measurements found that the atmosphere holds very little, if any, methane, a gas
that can be produced biologically.
-- The first determinations of the age of a rock on Mars and how long a rock
has been exposed to harmful radiation provide prospects for learning when water
flowed and for assessing degradation rates of organic compounds in rocks and
soils.
Curiosity paused in driving this spring to drill and collect a sample from a
sandstone site called Windjana. The rover currently is carrying some of the
rock-powder sample collected at the site for follow-up analysis.
"Windjana has more magnetite than previous samples we've analyzed," said
David Blake, principal investigator for Curiosity's Chemistry and Mineralogy
(CheMin) instrument at NASA’s Ames Research Center, Moffett Field, California.
"A key question is whether this magnetite is a component of the original basalt
or resulted from later processes, such as would happen in water-soaked basaltic
sediments. The answer is important to our understanding of habitability and the
nature of the early-Mars environment."
This map shows in red the route driven by NASA's
Curiosity Mars rover from the "Bradbury Landing" location where it landed in
August 2012 (blue star at upper right) to nearly the completion of its first
Martian year. The white line shows the planned route ahead.
Image Credit: NASA/JPL
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Preliminary indications are that the rock contains a more diverse mix of clay
minerals than was found in the mission's only previously drilled rocks, the
mudstone targets at Yellowknife Bay. Windjana also contains an unexpectedly high
amount of the mineral orthoclase, This is a potassium-rich feldspar that is one
of the most abundant minerals in Earth's crust that had never before been
definitively detected on Mars.
This finding implies that some rocks on the Gale Crater rim, from which the
Windjana sandstones are thought to have been derived, may have experienced
complex geological processing, such as multiple episodes of melting.
"It's too early for conclusions, but we expect the results to help us connect
what we learned at Yellowknife Bay to what we'll learn at Mount Sharp," said
John Grotzinger, Curiosity Project Scientist at the California Institute of
Technology, Pasadena. "Windjana is still within an area where a river flowed. We
see signs of a complex history of interaction between water and rock."
Curiosity departed Windjana in mid-May and is advancing westward. It has
covered about nine-tenths of a mile (1.5 kilometers) in 23 driving days and
brought the mission's odometer tally up to 4.9 miles (7.9 kilometers).
Since wheel damage prompted a slow-down in driving late in 2013, the mission
team has adjusted routes and driving methods to reduce the rate of damage.
For example, the mission team revised the planned route to future
destinations on the lower slope of an area called Mount Sharp, where scientists
expect geological layering will yield answers about ancient environments. Before
Curiosity landed, scientists anticipated that the rover would need to reach
Mount Sharp to meet the goal of determining whether the ancient environment was
favorable for life. They found an answer much closer to the landing site. The
findings so far have raised the bar for the work ahead. At Mount Sharp, the
mission team will seek evidence not only of habitability, but also of how
environments evolved and what conditions favored preservation of clues to
whether life existed there.
The entry gate to the mountain is a gap in a band of dunes edging the
mountain's northern flank that is approximately 2.4 miles (3.9 kilometers) ahead
of the rover's current location. The new path will take Curiosity across sandy
patches as well as rockier ground. Terrain mapping with use of imaging from
NASA's Mars Reconnaissance Orbiter enables the charting of safer, though longer,
routes.
The team expects its will need to continually adapt to the threats posed by
the terrain to the rover's wheels but does not expect this will be a determining
factor in the length of Curiosity's operational life.
"We are getting in some long drives using what we have learned," said Jim
Erickson, Curiosity Project Manager at NASA's Jet Propulsion Laboratory (JPL) in
Pasadena, California. "When you're exploring another planet, you expect
surprises. The sharp, embedded rocks were a bad surprise. Yellowknife Bay was a
good surprise."
JPL manages NASA's Mars Science Laboratory Project for NASA's Science Mission
Directorate at the agency’s headquarters in Washington, and built the project's
Curiosity rover.
For more information about Curiosity, visit:
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NASA
Guillermo Gonzalo Sánchez Achutegui
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