The UAE’s Hope probe has discovered a new type of proton aurora around Mars. Aurorae are ultraviolet lights that appear on the planet when solar activity disturbs the atmosphere.
The ‘patchy’ proton aurora potentially triggers new insights into unexpected behaviours in the Martian atmosphere.
The Emirates Mars Mission team has worked together with NASA’s MAVEN (Mars Atmosphere and Volatile Evolution) mission to fully characterise these observations.
“Our discovery of this 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. “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.”
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 localised energy deposition in the atmosphere.