Space

Curiosity takes self-portrait, sniffs Martian air

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High-Resolution Self-Portrait by Curiosity Rover Arm Camera used by NASA engineers to document the rover’s condition (Image: NASA/JPL-Caltech/Malin Space Science Systems)
SAM instrument being installed in Curiosity (Image: NASA/JPL-Caltech)
High-Resolution Self-Portrait by Curiosity Rover Arm Camera used by NASA engineers to document the rover’s condition (Image: NASA/JPL-Caltech/Malin Space Science Systems)
Graphic of the five most abundant gases in the Martian atmosphere (Image: NASA/JPL-Caltech, SAM/GSFC)
Potential sources and sinks of methane on Mars (Image: NASA/JPL-Caltech, SAM/GSFC)
Graphic showing sources of volatile molecules in the Martian atmosphere (Image: NASA/JPL-Caltech)
Results from the Sample Analysis at Mars instrument on NASA's Curiosity rover along with a Martian meteorite found on Earth with the same isotope ratios(Image: NASA/JPL-Caltech/JSC)
Lab demonstration of the measurement chamber inside the Tunable Laser Spectrometer, part of the Sample Analysis at Mars investigation on NASA's Curiosity rover (Image: NASA/JPL-Caltech)
The SAM instrument (Image: NASA)
The SAM instrument with side panels removed (Image: NASA)
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NASA’s Curiosity rover has taken a whiff of Martian air at the "Rocknest" site in Gale Crater. The robot explorer's Sample Analysis at Mars (SAM) instruments are now being used to measure the constituent elements of the atmosphere and their isotopes with the aim of providing insights into the history of the Red Planet and its chances of having once supported life.

The most notable thing about the Martian atmosphere is that there isn't that much of it. It’s 100 times thinner than Earth and composed of an unbreathable mixture of 95.9 percent carbon dioxide, two percent each of argon and 1.9 percent nitrogen with traces of oxygen, carbon monoxide and other elements. What’s interesting about the atmosphere is not its elements so much as their isotopes. That is, how heavy they are. It’s the isotopes that tell the real story.

Graphic showing sources of volatile molecules in the Martian atmosphere (Image: NASA/JPL-Caltech)

The presence of so much argon with so many heavy isotopes indicates that Mars may have had a heavier atmosphere in the the distant past, but most of it was lost with the lighter isotopes blowing off into interplanetary space. This left behind relatively heavy isotopes of argon and carbon. If this is the case, then the argument for a once-watery Mars becomes stronger.

An equally important find is methane in the Martian atmosphere – or rather, the lack of it. The Tunable Laser Spectrometer (TLS) in SAM is the most sensitive atmosphere-sniffing instrument ever sent to Mars, but it has sent back indications that the planet’s air contains less than a few parts per billion of methane or even none at all. Since methane on Earth is produced by biological as well as non-biological processes, this rules out what would have been one indicator of life still being present on Mars.

Graphic of the five most abundant gases in the Martian atmosphere (Image: NASA/JPL-Caltech, SAM/GSFC)

"Methane is clearly not an abundant gas at the Gale Crater site, if it is there at all. At this point in the mission we're just excited to be searching for it," said SAM TLS lead Chris Webster of NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California. "While we determine upper limits on low values, atmospheric variability in the Martian atmosphere could yet hold surprises for us."

At the moment, Curiosity's SAM laboratory analyzes air samples with two methods. The first is a mass spectrometer, which is used to study the full range of atmospheric gases and the other is the TLS, which focuses on carbon dioxide and methane. A third instrument that separates and identifies gases (called agas chromatograph) has yet to be used.

Say cheese

High-Resolution Self-Portrait by Curiosity Rover Arm Camera used by NASA engineers to document the rover’s condition (Image: NASA/JPL-Caltech/Malin Space Science Systems)

Another task that Curiosity recently carried out was to snap a high-definition self-portrait. This was more than just an attempt to take a striking image – these self-portraits provide scientists and engineers with a chronicle of Curiosity's condition as it carries out its two-year mission.

Next on SAM’s agenda will be to study its first solid sample with an emphasis on seeking water-bearing minerals and carbonates.

Ed's update

Thanks to all the readers who have questioned how this can be a self-portrait photo of the Curiosity Rover when no part of the vehicle appears to be holding the camera. The answer is that the image is actually a composite (or stitch) of 55 high resolution photographs taken with the Rover's Mars Hand Lens Imager (MAHLI). MAHLI is the only one of the Rover's cameras mounted on the end of a robotic arm. The arm holding the camera has been obscured in the process of creating the composite. The process also accounts for the somewhat warped perspective.Source: NASA

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6 comments
DOC HOLLYWOOD
Looks like Nevada. Must've been daytime when the pic was taken.It would appear that the place gets some decent sunlight.
Gaëtan Mahon
The first thing I thought of when I saw the Curiosity doing a picture of itself was a about a Girl standing in the Bathroom in front of a Mirror with her Cellphone doing the obligatory Duckface photo for Facebook.
What has the Internet done to me?
Ed Bax
Was this self portrait taken by a detached camera on a tripod or something? I don't see any camera arm connected to the vehicle....
Ken Dawson
How come we don't see the extended arm in the self portrait? Who's holding the camera?
Chris Knowles
And if there is an arm holding the camera, why photoshop it out? Weird.
Spriscilla the Queen of the Ocean
If you blink really fast and move your head from side to side you not only can see the arm but you can also see the friendly martians in the background.