When a barrage of charged protons and electrons approaches us from the sun, the earth’s magnetic field cleverly steers them around the planet. This flutter creates shimmering, glowing curtains of color known as the Aurora Borealis in the polar regions of the northern hemisphere and the Aurora Australis in the south.
The same phenomenon also occurs on Mars. But there it’s not just the Northern Lights and Southern Lights, but also the Equatorial Lights, the Mid-latitude Lights, the Eastern Lights, the Western Lights – all over the planet.
Launched by the United Arab Emirates and orbiting the red planet since February, the Hope spacecraft captured unique images of these dancing atmospheric lights known as discrete northern lights.
Mission officials released the pictures on Wednesday.
“This will open new doors for study when it comes to the Martian atmosphere,” said Hessa al-Matroushi, the scientific director of the UAE’s first interplanetary mission, “and how it interacts with solar activity.”
The embers on Mars are not only on the top and bottom of the planet, because the magnetic field around the planet has largely been extinguished as molten iron has cooled down inside. But parts of the Martian crust, which hardened several billion years ago when Mars still had a global magnetic field, retain part of this magnetism.
“They are very patchy and unevenly distributed,” said Justin Deighan, assistant director of science.
While the Earth’s magnetic field is like a large bar magnet, on Mars it is “more like taking a bag of magnets and throwing them into the planet’s crust,” said Dr. Deighan, a researcher at the University of Colorado Atmosphere and Space Physics Laboratory who is working with the UAE on the mission. “And they are all directed in different ways. And they have different strengths. “
The disjointed magnetic fields act as lenses to direct solar wind particles into different parts of the Martian atmosphere, but then they hit atoms and molecules in the upper atmosphere and create the glow of auroras.
Previous Mars orbiters have also observed the northern lights, but Hope, with an elevation orbit varying between 12,400 miles and 42,000 miles above the surface, may provide a global view of the night side of Mars.
Photographing the aurora borealis was not one of the core scientific observations planned for the Hope spacecraft, which entered orbit around Mars in February. The mission seeks to study the dynamics of the Martian atmosphere near the surface, which affects how quickly the Martian atmosphere escapes into space.
But even before the probe was launched, the scientists realized that one of the instruments that is making observations in the far ultraviolet part of the spectrum to measure oxygen and hydrogen levels in the upper atmosphere may also detect the northern lights.
“Our guess was that we would see something, but we weren’t sure how often it would be,” said Dr. Deighan. “The really amazing thing is that we basically saw it right away, and with such clarity. It was clear. “
NASA’s MAVEN spacecraft can also capture similar images of the Mars aurors as their elliptical orbit takes them further from the planet, and it can also directly measure and identify the solar particles that create the light show as they pass nearby. However, it cannot take both measurements at the same time.
By coordinating Hope’s aurora photos with MAVEN’s particle measurements, planetary scientists could potentially compile a more complete understanding of the night lights of Mars.
“Having two spaceships is really what you want for it,” said Dr. Deighan.