Country: NASA’s Martian Atmosphere and Variable Evolution (MAVEN) and the Emirati Hope Probe (EMM) have joined forces to study the ultraviolet aurora borealis that dances and glows high in the Martian atmosphere.
New research has discovered that these diurnal events are not always diffuse, featureless and evenly distributed, but are highly dynamic and variable, and contain minute structures.
“The aurora was so widespread and disorganized that the plasma environment around Mars must have been really turbulent, as the solar wind was directly affecting the upper atmosphere,” said planetary scientist Mike Chavin of the University of Colorado Boulder.
“By combining the EMM’s auroral observations with MAVEN’s measurements of the auroral plasma environment, we can confirm this hypothesis and determine that what we’re seeing was essentially a map of where the solar wind rains down on the planet.”
Proton auroras were described as “the most common auroras on the Red Planet” for the first time in 2018, as shown in the MAVEN data.
Martian auroras form somewhat similarly to how auroras form on Earth, however, since Mars is an entirely different beast, without an internally driven magnetosphere like Earth, the end result is unique to Mars.
Proton auroras are formed when positively charged protons in the solar wind collide with Mars’ hydrogen shell and ionize, stealing electrons from hydrogen atoms to become neutral. This charge exchange allows neutral particles to bypass the shock of the magnetic field around Mars, raining in the upper atmosphere and emitting light above purple.
This process was thought to reliably produce a uniform auroral emission over the course of Martian days, but new observations show otherwise.
Instead of the expected smooth profile, data from the Hope probe show that auroras are sometimes patchy, suggesting that there might be unknown processes during the formation of these aurorae.
NASA’s orbiter carries a full suite of plasma instruments to explore the solar wind, magnetic environment, and thermal ions in space around Mars.
In other words, the rare chaotic interaction between Mars and the solar wind is responsible for the patchy aurora, and there might be long-term effects on the atmosphere and water loss. Without a global magnetic field, Mars continues to lose both.
Interestingly, the proton auroras (both smooth and patchy), might help understand at least one of these, given that the hydrogen involved is created in part by water in the Martian atmosphere seeping into space.
“Several future data and modeling studies will be required to explore the full effects of these conditions on the evolution of the Martian atmosphere,” the researchers wrote.
Source: RT
