Auroras spreading across Martian skies are not only gorgeous exhibits, but they also provide scientists with major indicia regarding the way the Red Planet’s water eludes into its atmosphere.
A new report regarding this phenomenon was revealed on December 12th at the annual meeting of the American Geophysical Union (AGU). A particular type of aurora known as a proton aurora was first detected on Mars in 2016, with the help of data collected by the Mars Atmosphere and Volatile Evolution (MAVEN) probe. This aurora, which takes place during daytime and generates ultraviolet light, is not visible with the naked eye but was discovered by the spacecraft’s Imaging UltraViolet Spectrograph (IUVS) instrument.
Regular Stunning Phenomenon
Lately, scientists analyzed the Martian proton auroras, examining the data gathered over a few years of observations and describing their discoveries in a new paper. They found that these auroras are not at all rare, as they previously believed.
As a matter of fact, they are Mars‘ most regular aurora, and they are incredibly frequent. They have an approximately 100 percent occurrence rate on the daytime of the planet in southern summer, according to the lead research author Andréa Hughes, a doctoral candidate in engineering physics at Embry-Riddle Aeronautical University in Daytona Beach, Florida.
Auroras on Earth usually appear when jets of charged particles from the Sun, known as solar winds, crush into the planet’s magnetic field. The energetic impacts between solar particles and atmospheric gas particles make the sky glow, such as the northern and southern lights.
The Red Planet’s proton auroras are also caused by solar winds. However, in the case of these types of phenomenons, charged protons crash with a cloud of hydrogen that’s encompassing Mars. There, they absorb electrons from hydrogen atoms, which nullify the protons. When those energetic neutral atoms reach the lower atmosphere of the dry planet, their clashes with molecules generate ultraviolet lights, also known as proton auroras.
Not Visible With the Naked Eye
The reason why these auroras are so common during the southern summertime is that summer months are when the planet’s hydrogen cloud is completely positioned to regularly connect with solar winds and generate almost persistent proton auroras.
However, this is not all the scientists found out. As temperatures soar during summer months, rising dust clouds transport water vapor away from Mars’s surface.
“That causes hydrogen to break apart into hydrogen and oxygen, and that causes it to escape,” Hughes said. “Because of that — and because of the connection between solar wind protons interacting with the hydrogen in Mars’ atmosphere — we know that when we’re seeing proton aurora, the source of that is not only the solar wind but also this water that’s breaking apart and being lost to space.”
Now, you might be wondering if you’d be able to see a proton aurora if you were on the planet’s surface, but unfortunately, you wouldn’t.
“It’s not something that could be observed from the surface, because we’re looking at this in ultraviolet light, and ultraviolet is absorbed in the atmosphere. So by the time it gets to the surface, you wouldn’t see it,” Hughes explained.
The study was published on December 12th in the journal JGR Space Physics.