On clear Mars nights, long, snake-like streaks of light may spread across the sky for thousands of miles. It’s a beautiful sight, according to new observations from the United Arab Emirates Mission to Mars (EMM) — and it represents a strange new type of aurora that has not been seen on any planet.
The aurora borealis – also known in Land like the south or Northern lights They occur when charged particles from the solar wind collide with particles in the planet’s atmosphere. Several different types of aurora borealis have been detected on Mars, including Planet-wide “aurora borealis diffuse”which glow dimly across the entire Martian sky during severe solar storms, as well as patchy “discrete auroras,” which glow only over certain regions of Mars’ crust believed to contain magnetized minerals, according to EMM.
This new type of aurora – which EMM researchers have dubbed “split zigzag auroras” – appears to be a strange mixture of other types, the researchers said.
The new type of aurora appeared during a recent solar storm when charged electrons swept through the red planet’s thin atmosphere, visible only over certain areas of Mars’ view. As these particles rush into magnetic field lines in the atmosphere, long tendrils of light meander across the sky from the planet’s day side to its night side, along the planet’s radius, the EMM researchers said in an email statement.
The reason behind this newly discovered Martian aurora remains a mystery.
Rob Lillis, a planetary scientist at the University of California, Berkeley, who works on the UAE’s ultraviolet spectrophotometer, said in the statement. “We have ideas, but there’s no solid explanation for why we’re observing intense auroras of this shape and on planetary scales.”
EMM’s Hope orbiter, which has been scanning the planet from above since February 2021, spotted the new aurora borealis in ultraviolet Light, using an instrument called EMUS (Emirates Mars Ultraviolet Scale). According to the researchers, this type of light – invisible to the naked eye – shows where the electrons of the energetic solar wind collide. atoms and particles in Mars’ upper atmosphere, about 80 miles (130 kilometers) above the planet’s surface.
The team said that while scientists have detected separate auroras over certain patches of the Red Planet before, they had never seen one on this “enormous scale”. The researchers added that a solar storm that pushed charged particles into the Martian atmosphere at a faster and more turbulent rate than usual is likely a major factor in this type of long, twisting aurora.
Incidents of solar storms are expected to increase over the next several years as the Sun approaches its solar maximum—the 11-year period of greatest activity in the Sun’s cycle—in 2025. EMM’s Hope orbiter will continue to observe these newly discovered auroras. In the meantime, as scientists search archival data collected by NASA and the European Space Agency to look for more examples of snake-like stripes on Mars.
Originally published on Live Science.