NASA has announced that the MAVEN mission witnessed two kinds of ultraviolet aurora simultaneously. What's incredible is that this was for the first time in its eight years orbiting Mars.
Mars, our neighboring planet, has usually been considered to be a barren desert world where not much goes on. But this is far from the truth. In fact, Mars is a very active planet, both in its interior and exterior. Several missions on Mars, as well as those orbiting the red planet, have provided us with unprecedented insight into the planet. These new data have forced us to rethink everything we thought we knew about Mars. One mission specifically, InSight, provided never-before-seen data on the interior of the red planet. The mission, which is now likely to have come to an end, provided scientists with incredible data showing the red planet is geologically active. But scientists have not been researching Mars only from the surface. Several orbiters have provided much-needed data on Mars as well.
One such mission is called MAVEN, which is short for Mars Atmosphere and Volatile Evolution. NASA has announced that the MAVEN mission witnessed two kinds of ultraviolet aurora simultaneously. What’s incredible is that this was for the first time in its eight years orbiting Mars. NASA selected MAVEN as part of its now-canceled Mars Scout Program to study the planet’s atmosphere and ionosphere, including their interaction with the Sun. As the only asset on Mars that can simultaneously monitor the Sun’s activity and the thin Martian atmosphere, this orbiter is unique. MAVEN team members also accurately predicted when the developing solar storm would reach Mars based on real-time analysis and simulations of solar eruptions from NASA’s Moon to Mars Space Weather Analysis Office.
A light show
Mars lacks a global magnetic field to shield it against the damaging radiation solar storms can bring. This means accurate space weather forecasting is vital to protecting current missions and future human explorers. In August, a series of solar flares, which are intense bursts of radiation, were produced by an active region of the Sun. There was also a coronal mass ejection (CME) that followed the flare activity. A CME is a massive explosion of gas and magnetic energy that leaves the Sun and propagates across the solar system. Mars was impacted a few days later by this interplanetary CME. As a result of this CME, the MAVEN spacecraft observed a solar energetic particle (SEP) event.
It was among the brightest ever observed. MAVEN’s SEP detector observed solar energetic particles accelerating ahead of the CME on Aug. 27. The strength of the solar storm was measured by many of MAVEN’s instruments. Four instruments were used for this analysis: the Extreme Ultraviolet Monitor, the Magnetometer, the Solar Wind Ion Analyzer, and the Solar Wind Electron Analyzer.
To determine when the structure would arrive and impact Mars, we used space weather models of CME propagation, explained Christina Lee, a U.C. Berkeley space physicist. Lee is a member of the MAVEN mission team and collaborates with the Moon to Mars Space Weather Analysis Office. “This allowed the MAVEN team to anticipate some exciting disturbances in Mars’ atmosphere from the impacts of the interplanetary CME and the associated SEPs,” she explained. A solar storm unleashed particles that bombarded Mars’ atmosphere, causing bright ultraviolet auroras. Using MAVEN’s Imaging Ultraviolet Spectrograph (IUVS) instrument, diffuse and proton aurora was observed.
Why does this matter?
But what makes this observation so important and incredible? Timing played a part in why this extraordinary duo was spotted simultaneously. The dust storm season is over on Mars, which occurs every year when Mars approaches the Sun the closest. It is due to these dust storms that water vapor can reach high altitudes in the atmosphere. UV radiation breaks it up here, releasing hydrogen atoms. The planet’s dayside is lit up by ultraviolet emissions when the solar wind hits all this extra hydrogen. A diffuse aurora was visible all over the nightside as energic particles penetrated deeper into the atmosphere, accompanying the proton aurora and creating an even more dynamic aurora.
So, as you can see, Mars continues revealing its mysteries, secrets, and, most importantly, its beauties. The planet is showing us what a dynamic world it is. It also reaffirms theories and evidence that in the very distant past, Mars was a planet very similar to today’s Earth.