Atomic oxygen has been detected in the atmosphere of Mars for the first time since the last observation 40 years ago.
The discovery has been made by a flying space observatory, a Boeing 747 equipped with high-tech instruments, which flies at altitudes between 37,000 and 45,000 feet.
By flying so high, the instruments on board the Stratospheric Observatory for Infrared Astronomy (Sofia) are able to distinguish between the oxygen in the Earth’s atmosphere and that surrounding the red planet.
“Atomic oxygen in the Martian atmosphere is notoriously difficult to measure,” said Pamela Marcum, Sofia project scientist.
“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.”
The atomic oxygen was detected in a part of the Mars atmosphere known as the mesosphere.
But the measurements were not as expected.
“Scientists detected only about half the amount of oxygen expected, which may be due to variations in the Martian atmosphere,” said a Nasa spokesman. “Scientists will continue to use Sofia to study these variations to help better understand the atmosphere of the red planet.”
The advanced detectors on one of the observatory’s instruments, the German Receiver for Astronomy at Terahertz Frequencies (Great), are credited with distinguishing between the oxygen in the atmospheres on Mars and Earth.
Sofia is a joint project between Nasa and the German Aerospace Centre.