New findings from a joint European-Japanese spacecraft on its mission to Mercury reveal the presence of aurora on the small planet. This discovery leads scientists to believe that aurora, known for its stunning displays of greens, reds, and yellows at Earth’s highest latitudes, could potentially be found in various forms across the entire solar system.

Aurorae are created when charged particles, such as electrons, protons, or ions, are accelerated along the magnetic field lines of a planet.

The evidence of aurora on Mercury comes from data collected during a flyby of the BepiColumbo spacecraft, which is on its way to studying Mercury and is scheduled to enter orbit around the planet in 2026.

‘Southern Lights’ on Mercury

A recent study published in Nature Communications reveals the presence of “Southern Lights” around Mercury’s south pole.

This evidence was obtained during an earlier flyby on October 1, 2021, where BepiColumbo captured images and collected data on Mercury’s magnetosphere—the region dominated by the planet’s magnetic field.

Magnetic Appeal

The aurorae in Mercury’s southern magnetosphere are similar to those found on Earth and Mars, according to the study. Mercury’s magnetosphere undergoes changes based on the strength of the solar wind—a flow of charged particles emanating from the sun—similar to what occurs on Earth, Jupiter, Saturn, and Uranus.

BepiColumbo provided direct evidence of “X-ray aurorae,” indicating energetic electrons being accelerated in the tail of Mercury’s magnetosphere on its night-side and rapidly drifting towards its dayside, creating aurora-like phenomena.

The authors of the study suggest that this mechanism is likely a universal occurrence throughout the entire solar system.

Aurora on Other Planets

Aurorae have been observed in ultraviolet light on Jupiter, Saturn, Uranus, Neptune, Mars, and even the night side of Venus, despite the absence of a magnetic field on the latter two planets.

The BepiColumbo mission, launched in 2018, consists of two spacecraft equipped with orbiters—the ESA Mercury Planetary Orbiter (MPO) and the JAXA Mercury Magnetospheric Orbiter (MMO).

The MPO will primarily study Mercury’s surface and composition, while the MMO will focus on Mercury’s magnetic environment and the chemical makeup of its thin exosphere. Together, these orbiters will provide simultaneous investigations into how the solar wind impacts both the planet’s exosphere and its surface.

Wishing you clear skies and awe-inspiring sights.