When barrages of charged protons and electrons erupted from the sun are heading towards us, the Earth’s magnetic field deftly deflects them around the planet. These jerks generate shimmering and brilliant curtains of color known as the Aurora Borealis in the polar regions of the northern hemisphere and the Aurora Austral in the south.
This same phenomenon also occurs on Mars. But here it is not just the northern and southern lights, but also the equatorial lights, mid-latitude lights, eastern lights, western lights – all around the planet.
The Hope spacecraft, launched by the United Arab Emirates and orbiting the Red Planet since February, has captured unique images of these dancing atmospheric lights, known as discrete auroras.
Mission officials released the footage on Wednesday.
“This will open new doors for study regarding the Martian atmosphere,” said Hessa al-Matroushi, chief scientist of the UAE’s first interplanetary mission, “and how it interacts with the activity. solar”.
The glows on Mars aren’t just at the top and bottom of the planet, as the magnetic field around the planet largely died out when the molten iron inside cooled. But parts of Mars’ crust that hardened billions of years ago when Mars had a global magnetic field preserve some of that magnetism.
“They are very uneven and unevenly distributed,” said Justin Deighan, the deputy chief scientist.
While Earth’s magnetic field is like a large bar magnet, on Mars, “it’s more like you’ve taken a bag of magnets and thrown them into the crust of the planet,” said Dr. Deighan, a researcher at the University of Colorado Atmospheric Laboratory and Space Physics, who is collaborating with the United Arab Emirates on the mission. “And they’re all pointed in different ways. And they have different strengths.
The disjointed magnetic fields act like lenses to guide solar wind particles to different parts of the Martian atmosphere, but they then strike atoms and molecules in the upper atmosphere, generating the aurora glow.
Previous Mars orbiters have also observed auroras, but Hope, with a high-altitude orbit ranging from 12,400 miles to 27,000 miles above the surface, can have a global view of the night side of Mars.
Taking pictures of aurora was not among the main scientific observations planned for the Hope spacecraft, which entered orbit around Mars in February. The mission tries to study the dynamics of the Martian atmosphere near the surface which influence the speed at which the atmosphere of Mars leaks into space.
But even before the launch of the probe, scientists realized that one of the instruments, which makes observations in the far ultraviolet part of the spectrum to measure oxygen and hydrogen levels in the upper atmosphere, could also be able to detect aurora.
“Our guess was that we would see something, but we didn’t know how often it would happen,” Dr Deighan said. “What’s really fantastic is that we saw it right away and with such clarity. It was unambiguous. “
NASA’s MAVEN spacecraft can also take similar photos of Martian auroras as its elliptical orbit pulls it away from the planet, and it can also directly measure and identify the solar particles creating the light show as it passes nearby. But he cannot do both measurements simultaneously.
By coordinating Hope’s aurora photographs with MAVEN’s particle measurements, planetologists may be able to better understand the nocturnal lights of Mars.
“Having two spaceships is really what you want for this,” Dr Deighan said.