NASA’s SOFIA Observatory Detects Atomic Oxygen in Upper Atmosphere of Mars

NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA), the largest airborne observatory in the world, has detected atomic oxygen in the upper layers of the Martian atmosphere.

The German REceiver for Astronomy at Terahertz frequencies (GREAT) instrument onboard the SOFIA aircraft enabled researchers to distinguish the oxygen in the Martian atmosphere from oxygen in Earth’s atmosphere.

“Atomic oxygen in the Martian atmosphere is notoriously difficult to measure,” said Dr. Pamela Marcum, project scientist for SOFIA at NASA Ames Research Center.

“To observe the far-infrared wavelengths needed to detect atomic oxygen, researchers must be above the majority of Earth’s atmosphere and use highly sensitive instruments, in this case a spectrometer.”

“SOFIA provides both capabilities,” she said.

According to the scientists, atomic oxygen is the key element in several processes governing the energy and mass flow in the atmosphere of Mars.

They detected only about half the amount of oxygen expected, which may be due to variations in the planet’s atmosphere.

“We will continue to use SOFIA to study the variations to help better understand the atmosphere of the Red Planet,” they said.

The researchers presented their findings in a paper published in the journal Astronomy and Astrophysics.

“The detection of the OI (oxygen) line in the Martian atmosphere is an important accomplishment that will allow us to gain novel scientific knowledge on this atomic species, which is very difficult to obtain by any other method,” they explained in the paper.

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L. Rezac et al. 2015. First detection of the 63 μm atomic oxygen line in the thermosphere of Mars with GREAT/SOFIA. A&A 580, L10; doi: 10.1051/0004-6361/201526377