The MAVEN (Mars Atmosphere and Volatile Evolution) project of NASA and the Emirates Mars Mission (EMM) of the United Arab Emirates have revealed cooperative observations of dynamic proton aurora occurrences on Mars. EMM's remote auroral observations, along with MAVEN's in-situ plasma investigations, bring up new paths for comprehending the Martian atmosphere. This collaboration was enabled by recent data exchange between the two missions, and it emphasizes the importance of multi-point observations in space. These findings were published in the journal Geophysical Research Letters.
EMM observed fine-scale features in proton aurora that spanned the whole day side of Mars in the latest research. MAVEN detected proton aurora in 2018, which is a type of Martian aurora formed when the solar wind, which is made up of charged particles from the Sun, interacts with the upper atmosphere. Typical proton aurora measurements by MAVEN and the ESA's Mars Express mission indicate this aurora to be smooth and equally dispersed over the globe. EMM, on the other hand, saw proton aurora which looked to be very dynamic and varied. When turbulent circumstances surrounding Mars allow charged particles to flow directly into the atmosphere and light when they calm down, these "patchy proton aurora" emerge.
According to Mike Chaffin, a MAVEN and EMM scientist based at the University of Colorado Boulder's Laboratory for Atmospheric and Space Physics and the study's lead author, "EMM's observations suggested that the aurora was so widespread and disorganized that the plasma environment around Mars must have been truly disturbed, to the point where the solar wind was directly impacting the upper atmosphere wherever we observed auroral emission." We can corroborate this idea and verify that what we were seeing was basically a map of where the solar wind was showering down on the earth by integrating EMM auroral observations with MAVEN measurements of the auroral plasma environment.
Normally it is difficult for the solar wind to reach Mars' upper atmosphere because it is diverted by the bow shock and magnetic fields around the planet. The patchy proton aurora measurements are therefore a window into the unusual case where the Mars-solar wind interaction is chaotic.
The complete impact of these circumstances on the Martian atmosphere, according to Chaffin, is unclear, but EMM and MAVEN data will be critical in comprehending these mysterious phenomena.
Scientists have been able to establish the causes of the patchy proton aurora thanks to data exchange between MAVEN and EMM. The Emirates Mars Ultraviolet Spectrograph (EMUS) instrument is aboard EMM, and it scans the Red Planet's upper atmosphere and exosphere for variations in atmospheric composition and atmospheric escape to space. MAVEN is equipped with a comprehensive suite of plasma instruments, including the Magnetometer (MAG), the Solar Wind Ion Analyzer (SWIA), and the SupraThermal And Thermal Ion Composition (STATIC) instrument utilized in this study.
According to Shannon Curry of UC Berkeley's Space Sciences Laboratory, MAVEN Principal Investigator, EMM's global observations of the upper atmosphere give a unique viewpoint on an area essential to MAVEN science. These kinds of simultaneous observations delve into the underlying physics of atmospheric dynamics and development, highlighting the advantages of worldwide scientific collaboration.
Hessa Al Matroushi, EMM Science Lead, concurred.
She stated that access to MAVEN data was critical for contextualizing these new EMM findings. We're pushing the limits of our present knowledge of not only Mars but also planetary interactions with the solar wind.
Measurements from several perspectives have previously proved useful in Earth and heliophysics studies. Over a half-dozen, Mars orbiters are already collecting scientific data, and with the southern hemisphere of Mars presently experiencing summer, when proton aurora is believed to be most active, multi-vantage-point observations will be important to understand how these phenomena arise. The partnership of EMM and MAVEN underscores the importance of discovery-level science concerning the Martian atmosphere with two spacecraft monitoring the same location at the same time.
Journal Information: Michael S. Chaffin et al, Patchy Proton Aurora at Mars: A Global View of Solar Wind Precipitation Across the Martian Dayside From EMM/EMUS, Geophysical Research Letters (2022). DOI: 10.1029/2022GL099881