Astronomers have finally detected an aurora on Neptune using the James Webb Space Telescope (JWST). Researchers observed an infrared auroral glow and the spectral signature of a key tracer of aurorae in Neptune’s upper atmosphere. This detection confirms theories that Neptune should have aurorae, which were previously undetectable.
Aurorae occur when charged particles from the solar wind or nearby moons interact with a planet’s magnetosphere and upper atmosphere. The detection of an aurora on Neptune is significant, as it provides valuable insight into the space environment of the planet. Neptune’s magnetic field is particularly interesting, as models suggest that its aurorae should be traceable by a specific molecule.
The JWST detected an infrared auroral glow and a shockingly clear spectrum of this molecule, which suggests that Neptune’s upper atmosphere has cooled significantly since Voyager 2’s flyby 34 years ago. The intensity of the signal indicates that the upper atmosphere generating the aurora is around 85°C (358 K), a significant cooldown from the previously measured temperature.
The detection of an aurora on Neptune completes the set of giant planet aurorae, as all four planets (Jupiter, Saturn, Uranus, and now Neptune) have been detected. This discovery has far-reaching implications for understanding the inner workings of Neptune’s magnetosphere and the effects of solar activity on its atmosphere.
Future studies will focus on tracing the aurora to specific latitudes and longitudes and learning more about what drives its behavior. The team plans to conduct further observations using JWST to better understand Neptune’s aurorae and their responses to different levels of solar activity.
Source: https://eos.org/articles/after-30-year-search-scientists-finally-find-an-aurora-on-neptune