An anonymous reader quotes a report from CNN: Atomic oxygen has been detected in the atmosphere of Mars, according to NASA. The atoms were discovered in the Martian mesosphere, the upper layers of the red planet's atmosphere. This discovery will enable researchers to have a better understanding of the elusive Martian atmosphere. Atomic oxygen can help scientists determine atmospheric erosion and how other gases escape Mars. It also affects the radiative cooling from the carbon-dioxide bands in the Martian thermosphere, which is above the mesosphere. The atomic oxygen discovery was made using an instrument on board the Stratospheric Observatory for Infrared Astronomy, or SOFIA. SOFIA is a Boeing 747SP jet that has been modified for research purposes to carry a 100-inch diameter telescope. Using the German Receiver for Astronomy at Terahertz Frequencies, known as GREAT, allowed researchers to distinguish between oxygen from our atmosphere and that of the Martian atmosphere. They discovered half the amount of atomic oxygen expected, most likely due to variations in the atmosphere itself, and scientists will continue to use SOFIA to study the Martian atmosphere.