Dubai: Images of a ghostly glow known as Mars’ Discrete Aurora taken by Hope Probe’s EMUS (Emirates Mars Ultraviolet Spectrometer) instrument were released by the Emirates Mars Mission (EMM) on Wednesday.
His Highness Sheikh Mohammed bin Rashid Al Maktoum, Vice-President and Prime Minister of the UAE and Ruler of Dubai, also tweeted about the Martian phenomenon and said: “The UAE’s Hope Probe, first-ever Arab interplanetary mission, has captured the first global images of Mars’ Discrete Aurora. The high-quality images open up unprecedented potential for the global science community to investigate solar interactions with Mars.”
An aurora is a natural phenomenon, which is characterised by a display of a natural-coloured (green, red, yellow or white) light show, which is caused when electrically-charged particles from the sun collide with particles from gases such as oxygen and nitrogen present in the atmosphere.
A type of Martian aurora first identified by Nasa’s MAVEN spacecraft in 2016 is actually the most common form of aurora occurring on the Red Planet. According to scientists, the aurora can help them track water loss from Mars’ atmosphere.
According to EMM, the images taken by Hope Probe “have revolutionary implications for our understanding of the interactions between solar radiation, Mars’ magnetic fields and the planetary atmosphere.”
“These unique global snapshots of the Discrete Aurora of Mars are the first time such detailed and clear observations have been made globally, as well as across previously unobservable wavelengths. The implications for our understanding of Mars’ atmospheric and magnetospheric science are tremendous and provide new support to the theory that solar storms are not necessary to drive Mars’ aurora,’ said Hessa Al Matroushi, EMM Science Lead.
Mars’ magnetic fields
The ghostly glow known as Discrete Aurora is an intricate pattern that traces out the regions where Mars’ enigmatic crustal magnetic fields act like a funnel to guide fast electrons from space down into the atmosphere, causing it to shimmer in a manner similar to the Earth’s aurora.
EMM said: “This influence of localised magnetic fields is a unique feature of the Red Planet as Mars, unlike Earth, does not have a global magnetic field generated by the planet’s core. The most sensitive ultraviolet instrument yet to orbit Mars, EMUS is able to image these dynamic auroral events globally at high resolution and across a wide range of wavelengths, providing an unprecedented window upon the interaction of the atmosphere with solar particles.”
While previous studies had theorised the Discrete Aurora is tied to Mars’ magnetic fields and existing observations had been consistent with that theory, prior images of this phenomenon at this quality had only been available as artist’s impressions.
EMM Deputy Science Lead Justin Deighan said: “We have totally blown out ten years of study of Mars’ auroras with ten minutes of observations. The data we are capturing confirms the tremendous potential we now have of exploring Mars’ aurora and the interactions between Mars’ magnetic fields, atmosphere and solar particles with a coverage and sensitivity we could only previously dream of. These exciting observations go above and beyond the original science goals of the Emirates Mars Mission.”
The principal science goal of EMUS — one of three instruments on board the Mars Hope Probe — is the measurement of oxygen and carbon monoxide in Mars’ thermosphere and the variability of hydrogen and oxygen in the exosphere. Members of the science team who had previously worked on the MAVEN Mission had recognised the potential for the more sensitive EMUS instrument to capture new aspects of Mars’ auroral phenomena, but the results of early observations have exceeded their wildest expectations.
Three types of aurora have been observed around Mars to date: The Diffuse Aurora are observed only during intense solar storms, when interactions with the highest energy particles cause the atmosphere around the entire planet to light up.
In contrast, the Discrete Aurora is highly-localised and observations made to date have appeared to bear out the theory that it is directly linked to the patchy magnetic fields produced by the magnetised minerals embedded in Mars’ surface. Both of these aurorae are observed on Mars’ night side, while a third class, the Proton Aurora, has been measured on Mars’ day side and is driven by interactions between the solar wind and Hydrogen in Mars’ exosphere.
These three types of aurorae had previously been identified by ultraviolet instruments aboard the Mars Express and MAVEN missions orbiting Mars, but clear global images of the discrete aurora were elusive until the new observations by EMM.
Contribution to global scientific community
Matroushi noted: “Mars’ aurorae are an area of intense interest to the global scientific community and their study has tremendous potential to challenge, expand and deepen our understanding of Mars’ atmosphere and its interaction with the planet and with solar energies.
“We were hopeful that EMUS could make a contribution in this area but we now know with absolute certainty that contribution is going to be ground breaking,” she added.
Hope Probe, the first Arab interplanetary mission, is following its planned 20,000-43,000km elliptical science orbit, with an inclination to Mars of 25 degrees. The probe will complete one orbit of the planet every 55 hours and will capture a full planetary data sample every nine days in a two-year mission to map Mar’s atmospheric dynamics.