Atomic oxygen detected in Martian atmosphere

By Ashley Strickland, CNN

Updated 1539 GMT (2339 HKT) May 10, 2016

A self-portrait taken by NASA's Curiosity rover on June 15, 2018. A Martian dust storm has reduced sunlight and visibility around the planet, including at the rover's location in Gale Crater.
Photos: NASA's Mars Curiosity Rover
A self-portrait taken by NASA's Curiosity rover on June 15, 2018. A Martian dust storm has reduced sunlight and visibility around the planet, including at the rover's location in Gale Crater.
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NASA's Mars Curiosity Rover tweeted out a new image on January 23, 2018: "I'm back! Did you miss me?" The selfie is part of a fresh batch of images the rover beamed back from Mars.
Photos: NASA's Mars Curiosity Rover
NASA's Mars Curiosity Rover tweeted out a new image on January 23, 2018: "I'm back! Did you miss me?" The selfie is part of a fresh batch of images the rover beamed back from Mars.
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Five years ago and 154 million miles away, NASA's Curiosity Mars rover successfully landed on the planet. Take a look back at what the rover has been up to these past five years, including this selfie it took on January 19, 2016.
Photos: NASA's Mars Curiosity Rover
Five years ago and 154 million miles away, NASA's Curiosity Mars rover successfully landed on the planet. Take a look back at what the rover has been up to these past five years, including this selfie it took on January 19, 2016.
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The bright blue speck in the middle of this image is NASA's Curiosity Mars rover. The image was taken from another NASA spacecraft, Mars Reconnaissance Orbiter, which is in orbit above the planet, on June 6, 2017.
Photos: NASA's Mars Curiosity Rover
The bright blue speck in the middle of this image is NASA's Curiosity Mars rover. The image was taken from another NASA spacecraft, Mars Reconnaissance Orbiter, which is in orbit above the planet, on June 6, 2017.
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Curiosity has temperature and humidity sensors mounted on its mast. <a href="https://mars.nasa.gov/news/nasa-mars-rovers-weather-data-bolster-case-for-brine" target="_blank">Calculations</a> in 2015 based on Curiosity's measurements<a href="http://www.cnn.com/2015/04/14/us/mars-water-feat/index.html" target="_blank"> indicate</a> that Mars could be dotted with tiny puddles of salty water at night.
Photos: NASA's Mars Curiosity Rover
Curiosity has temperature and humidity sensors mounted on its mast. Calculations in 2015 based on Curiosity's measurements indicate that Mars could be dotted with tiny puddles of salty water at night.
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The Mars rover Curiosity does a test drill on a rock dubbed "Bonanza King" to determine whether it would be a good place to dig deeper and take a sample. But after the rock shifted, the test was stopped.
Photos: NASA's Mars Curiosity Rover
The Mars rover Curiosity does a test drill on a rock dubbed "Bonanza King" to determine whether it would be a good place to dig deeper and take a sample. But after the rock shifted, the test was stopped.
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Wheel tracks from Curiosity are seen on the sandy floor of a lowland area dubbed "Hidden Valley" in this image.
Photos: NASA's Mars Curiosity Rover
Wheel tracks from Curiosity are seen on the sandy floor of a lowland area dubbed "Hidden Valley" in this image.
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The rover recently encountered this iron meteorite, which NASA named "Lebanon." This find is similar in shape and luster to iron meteorites found on Mars by the previous generation of rovers. A portion of the rock was outlined by NASA scientists.
Photos: NASA's Mars Curiosity Rover
The rover recently encountered this iron meteorite, which NASA named "Lebanon." This find is similar in shape and luster to iron meteorites found on Mars by the previous generation of rovers. A portion of the rock was outlined by NASA scientists.
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Curiosity took this nighttime photo of a hole it drilled May 5 to collect soil samples. NASA said this image combines eight exposures taken after dark on May 13.
Photos: NASA's Mars Curiosity Rover
Curiosity took this nighttime photo of a hole it drilled May 5 to collect soil samples. NASA said this image combines eight exposures taken after dark on May 13.
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This view of the twilight sky and Martian horizon, taken by Curiosity, includes Earth as the brightest point of light in the night sky. Earth is a little left of center in the image, and our moon is just below Earth. A human observer with normal vision, if standing on Mars, could easily see Earth and the moon as two distinct, bright "evening stars."