James Webb telescope uncovers sensation There are auroras on Neptune
After 36 years of unsuccessful searching, NASA 's James Webb Space Telescope has captured the first images of auroras on Neptune. Long suspected but never observed, these celestial lights provide scientists with valuable data on the interactions between solar particles and the atypical magnetosphere of the icy planet.
Since the Voyager 2 space probe flew past Neptune in 1989, astronomers have suspected that auroras exist on the distant planet.
The phenomenon, which is known from Earth but can also be seen on Mars, Jupiter, Saturn and Uranus, has so far remained undetectable on Neptune. This is mainly due to its unusual magnetic field, which is inclined by 47 degrees to its axis of rotation.
In contrast to the auroras on Earth, which are concentrated at the poles, those observed on Neptune occur even at latitudes close to the equator.
A technical masterpiece from the Webb telescope
The discovery, published in Nature Astronomy, shows that the Webb telescope's NIRSpec infrared spectrograph has captured detailed images of these phenomena, which can be seen as cyan-colored patches of light.
This technological feat is the result of the telescope's exceptional ability to detect cationic trihydrogen (H3+), a typical chemical marker for the aurora on gas giant planets.
Heidi Hammel, astronomer and co-author of the study published in the journal Nature Astronomy, explains: "If the JWST can observe the first galaxies in the universe, it was only logical that it could also detect the aurora on Neptune. Thanks to its unprecedented infrared capabilities, we have finally been able to make these long-awaited observations."
The Webb telescope continues to take spectacular images of space. Like this image below, which shows the edge of a nearby young star-forming region NGC 3324 in the Carina Nebula. (Published by NASA on July 12, 2022) The image was taken by the James Webb Space Telescope's Near Infrared Camera (NIRCam) in infrared light and, according to NASA, reveals previously obscured areas of star formation.
Surprising cooling of the atmosphere
The data from the James Webb telescope also reveal another unexpected discovery: a significant drop in the temperature of Neptune's upper atmosphere. It is now twice as cold as it was in 1989, indicating a large and fascinating atmospheric change, despite the planet's great distance from the Sun.
9 facts about Neptune
- Planet type: Ice giant (no wonder, as it is 30 times further away from the sun than the Earth)
- Radius: 24,622 km
- Mass: 1.02413×10^26 kg
- Average distance from Earth: 4.5 billion km
- Surface temperature: -218 to -200 °C
- Length of the solar day: 0.6713 Earth day
- Length of year: 164.8 earth years
- Age: 4.503 billion years
- Named after: the Roman god of the sea
- Extra: Neptune was the first planet to be determined by purely mathematical calculations.
A window for future discoveries
These results pave the way for further in-depth investigations. An intensive observation campaign is planned for 2026, during which the telescope will observe Neptune for an entire month.
This future research will help to better understand the complex mechanisms of this mysterious planet at the edge of our solar system.
