For the first time in 40 years, NASA has detected atomic oxygen in Mars’ atmosphere, thanks to the Stratospheric Observatory for Infrared Astronomy (SOFIA), which soars 13.7 kilometres (45,000 feet) above Earth. The oxgyen atoms were found in the Martian upper atmosphere, known as the mesosphere.
The discovery could help astronomers identify how gases escaped from the Red Planet long ago. While this is super exciting for our understanding of Mars, humanity’s potential new home – the researchers found only half the amount of oxygen they expected, but this could be the result of variations in the atmosphere.
The last time atomic oxygen was observed in the Martian atmosphere was during the Viking and Mariner missions of the 1970s. So why such a long gap? Well, there’s really one thing to blame: Earth’s blue skies.
"Atomic oxygen in the Martian atmosphere is notoriously difficult to measure," said SOFIA project scientist, Pamela Marcum. "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."
Yup, researchers have been at war with Earth’s skies for decades now, because it’s dense and moist enough to make it extremely difficult to accurately see the Universe lying beyond it. So, to overcome this problem, researchers have implemented a bunch of workarounds (like making fake stars with giant lasers), which is where SOFIA comes in.
For the uninitiated, SOFIA is basically a giant aeroplane – a Boeing 747SP jetliner – with a large, 254-cm (100-inch) diameter telescope on it that can soar above most of Earth’s atmosphere to provide a clear picture.
Having such a high vantage point, in addition to specialised equipment that’s designed to ignore Earth’s atmosphere, enabled the team to make their calculations.
While the team hasn’t given any exact figures on just how much atomic oxygen is in the Martian mesosphere, they do state that it was lower than expected. Because of this, the team will continue to use SOFIA to gauge other areas of the planet to ensure this figure isn’t the result of simple variations in the atmosphere.