Using Webb’s Near-Infrared Spectrograph in June 2023, scientists not only captured the first direct image of Neptune’s auroras but also analyzed the planet’s atmospheric composition. Their ...

Hints of auroras were first faintly detected in ultraviolet light during a flyby of the Voyager 2 spacecraft in 1989. Webb captured Neptune’s shimmering lights in infrared light, providing ...

But on Neptune, the auroras are in very different areas. Hints of auroras were first faintly detected in ultraviolet light when the Voyager 2 spacecraft flew past Neptune in 1989.

The difference is owed to Neptune's magnetic field, which—as noted by Voyager 2—is tilted by 47 degrees, thus pushing the auroras away from Neptune's rotational poles.

That odd geometry is part of what makes Neptune so hard to study. The planet’s magnetic field is completely lopsided, which may explain why its auroras don’t behave like those on other planets.

Neptune's auroras occur near the mid-latitudes of the planet, not the polar regions, because of differences in its magnetic field, which determine the span of auroras, said O’Donoghue.

NASA notes that Neptune's auroras are unlike Earth's, Jupiter's, and Saturn's in that they aren't confined to the northern and southern poles. Instead, the ice giant's lights sit at the planet's ...