For the first time in 40
years, NASA researchers have detected atomic oxygen in Mars' atmosphere, thanks
to the Stratospheric Observatory for Infrared Astronomy (SOFIA), which soars on
a plane 13.7 kilometres (45,000 feet) above Earth. The oxgyen atoms were
found in the Martian upper atmosphere - known as the mesosphere - and 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.
In other words, it looks
like we have to wait for the full results.
