For the first time ever, a robot on Mars captured an aurora that’s visible to the human eye. The Perseverance rover recorded the phenomenon on March 18, 2024, as it observed the night sky over Jezero Crater.
Auroras are caused by interactions between solar particles and a planet’s magnetic field and atmosphere. Scientists have detected various types of auroras, but those on Mars were previously invisible to human eyes due to their ultraviolet wavelengths.
Phyicist Elise Wright Knutsen from the University of Oslo explained that observing visible auroras can help study how the Sun affects planets. The detection of a green glow opens new avenues for research, potentially leading to simpler and cheaper methods.
The Martian atmosphere is thin, with particles guided by its weak magnetic field towards the poles where they collide with materials, creating a glow in specific wavelengths. Previous studies detected ultraviolet auroras but not visible ones.
A team of scientists used this knowledge to predict the appearance of a green glow at 557.7-nanometer wavelength, which is ionized oxygen and corresponds to Earth’s green aurora color. They successfully recorded an excess light in the night sky using Perseverance instruments.
Unlike Earth’s auroras, which appear as structured ribbons, the Martian green glow is uniform throughout the sky. The team plans to study more solar storms and their effects on Mars’ atmosphere to understand how auroras work.
Source: https://www.sciencealert.com/the-martian-night-sky-was-seen-turning-green-in-a-stunning-first