Dubai, UAE: The Emirates Mars Mission, the first interplanetary exploration undertaken by an Arab nation, has made first observations of a new type of proton aurora around Mars.
The spatially variable ‘patchy’ proton aurora potentially triggers new insights into unexpected behaviors in the Martian atmosphere, an official statement said.
The EMM team has worked together with NASA’s MAVEN (Mars Atmosphere and Volatile Evolution) mission to fully characterize these observations.
This new patchy type of proton aurora is formed when the solar wind directly impacts Mars’ dayside upper atmosphere and emits ultraviolet light as it slows down.
It was discovered in snapshots of the dayside disk obtained by the Emirates Mars Ultraviolet Spectrometer (EMUS), which observes the planet’s upper atmosphere and exosphere, scanning for variability in atmospheric composition and atmospheric escape to space.
The aurora manifests as bright regions scattered across the dayside of the planet in two ultraviolet wavelengths associated with the Hydrogen atom, Lyman beta at 102.6 nm and Lyman alpha at 121.6 nm.
Under normal conditions, the dayside disk of the planet at these wavelengths is uniform, and the planetary brightness results from Hydrogen atoms scattering sunlight. When the aurora occurs, small regions of the planet become much brighter at these wavelengths, signifying intense localized energy deposition in the atmosphere.
The combination of EMM’s unprecedented global aurora images with MAVEN’s simultaneous local plasma observations opens up new avenues for understanding the drivers of Mars’ enigmatic aurora.
“Our discovery of these patchy proton aurora adds a new kind of event to the long list of those currently studied by EMM and challenges our existing views of how the proton aurora on Mars’ dayside are formed,” said Hessa Al Matroushi, EMM’s Science Lead.
Matroushi said the EMM Hope probe has so far uncovered many unexpected phenomena that extend our understanding of Mars’ atmospheric and magnetospheric dynamics.
“These new observations, combined with MAVEN data, have lifted the lid on entirely new possibilities for scientific research,” she added.
Mike Chaffin, EMM science team member and lead author of a newly submitted paper on the proton aurora, said, “We’ve seen emissions at these wavelengths before, thanks to proton aurora studies by NASA’s MAVEN mission, but these EMM EMUS images represent the first time we’ve had a global view of spatial variability in proton aurora at Mars, and the first time we’ve been able to unambiguously observe this patchy structure.”
“We know that these wavelengths are only emitted by the Hydrogen atom, which tells us that super energetic Hydrogen atoms must be present in the atmosphere in order to produce the auroral emission,” he said.
A data sharing agreement between EMM and MAVEN has enabled analysis of the new EMM images using plasma observations made by MAVEN, which has been characterizing the Mars ionosphere and magnetosphere since 2014.
MAVEN carries a full suite of plasma instruments, including a magnetometer and two ion electrostatic analyzers that measured the Martian plasma and fields environment during EMM’s observations of patchy proton aurora events.
As of June 2022, Mars is about a month away from the peak of its Southern Summer, when proton aurora are known to be at their most active. “Whether we’ll see anything as spectacular as what we’ve already got is anyone’s guess, but I’m hopeful. Hope continues to far exceed our expectations for scientific discovery, and I can’t wait to see what we learn next.” said Chaffin.