The MAVEN (Mars Atmosphere and Volatile Evolution) mission of NASA and the Emirates Mars Mission (EMM) of the United Arab Emirates has made joint observations of dynamic proton aurora occurrences at Mars. The combination of in-situ plasma investigations by MAVEN and remote auroral observations by EMM opens up new perspectives on the Martian atmosphere.
This partnership, which shows the utility of multi-point observations in space, was made feasible by recent data exchange between the two missions. A study of these findings appears in the journal Geophysical Research Letters.
In the latest research, EMM found tiny structures in the proton aurora that encompassed the entire dayside of Mars. A type of Mars aurora called a proton aurora was found by MAVEN in 2018; it forms when the solar wind, which is made up of charged particles from the Sun, interacts with the upper atmosphere.
Typical proton aurora observations made by MAVEN and ESA’s (the European Space Agency) Mars Express mission show these aurora appearing smooth and evenly distributed across the hemisphere.
By contrast, EMM observed proton aurora that appeared highly dynamic and variable. As the charged particles from Mars may flow directly into the atmosphere and glow as they slow down, this is how the “patchy proton aurora” is created.
“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 that the solar wind was directly impacting the upper atmosphere wherever we observed auroral emission,” said Mike Chaffin, a MAVEN and EMM scientist based at the Laboratory for Atmospheric and Space Physics at the University of Colorado Boulder and lead author of the study.
“By combining EMM auroral observations with MAVEN measurements of the auroral plasma environment, we can confirm this hypothesis and determine that what we were seeing was essentially a map of where the solar wind was raining down onto the planet.”
EMM’s global observations of the upper atmosphere provide a unique perspective on a region critical to MAVEN science. These types of simultaneous observations probe the fundamental physics of atmospheric dynamics and evolution and highlight the benefits of international scientific collaboration.
Shannon Curry
The bow shock and magnetic fields that encircle the planet usually cause the solar wind to be diverted, making it challenging for it to reach Mars’ upper atmosphere. So, the patchy proton aurora data provide a window into the infrequent instances when the chaotic Mars-solar wind interaction occurs.
“The full impact of these conditions on the Martian atmosphere is unknown, but EMM and MAVEN observations will play a key role in understanding these enigmatic events,” said Chaffin.
The data-sharing between MAVEN and EMM has enabled scientists to determine the drivers behind the patchy proton aurora. EMM carries the Emirates Mars Ultraviolet Spectrograph (EMUS) instrument, which observes the Red Planet’s upper atmosphere and exosphere, scanning for variability in atmospheric composition and atmospheric escape to space.
MAVEN carries a full suite of plasma instruments, including the Magnetometer (MAG), the Solar Wind Ion Analyzer (SWIA), and the SupraThermal And Thermal Ion Composition (STATIC) instrument used in this study.
“EMM’s global observations of the upper atmosphere provide a unique perspective on a region critical to MAVEN science,” said MAVEN Principal Investigator Shannon Curry, of UC Berkeley’s Space Sciences Laboratory. “These types of simultaneous observations probe the fundamental physics of atmospheric dynamics and evolution and highlight the benefits of international scientific collaboration.”
EMM Science Lead Hessa Al Matroushi agreed. “Access to MAVEN data has been essential for placing these new EMM observations into a wider context,” she said. “Together, we’re pushing the boundaries of our existing knowledge not only of Mars but of planetary interactions with the solar wind.”
Multi-vantage-point measurements have already proven to be an asset in Earth and heliophysics research. Since the southern hemisphere of Mars is currently experiencing summer, when proton aurora are known to be most active, more than six orbiters are currently performing science investigations there.
As a result, multi-vantage-point observations will be crucial to understanding how these events develop. With two spacecraft simultaneously observing the same area, the partnership between EMM and MAVEN exemplifies the value of discovery-level science regarding the Martian atmosphere.
MAVEN’s principal investigator is based at the University of California, Berkeley, while NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the MAVEN mission. Lockheed Martin Space built the spacecraft and is responsible for mission operations.
NASA’s Jet Propulsion Laboratory in Southern California provides navigation and Deep Space Network support. The University of Colorado Boulder’s Laboratory for Atmospheric and Space Physics (LASP) is in charge of overseeing science operations as well as public outreach and communication.
