[이데일리 김혜선 기자] A clear picture of Neptune taken by the world’s best space telescope is a hot topic. Voyager 2, a space probe launched by the United States in 1977, approached Neptune in 1989 and took pictures of the blue sphere. The Webb telescope released a new image of Neptune as a pale icy star last year, and recently, a study was published that Neptune’s clouds change according to the cycle of solar activity. Photos of Neptune taken by the James Webb Telescope. (Photo = NASA James Webb website) Neptune is the most distant planet in the solar system. Neptune’s atmosphere is surrounded by hydrogen, helium, and methane, which reflect blue light from the sun. This is why the images of Neptune taken by Voyager 2 or the Hubble telescope have been blue spheres. However, the Webb telescope removed Neptune’s atmosphere with a near-infrared camera and took a clear picture of the ‘icy planet’, where water, ammonia and methane were frozen.
On the 17th of last month, research results were also released showing that Neptune’s methane cloud was almost disappearing. Imke de Parter, a professor at the Department of Astronomy at the University of California, Berkeley (UC Berkeley), has observed Neptune for a long time using the Hubble Telescope and reported to the international academic journal ‘Icarus’ that Neptune’s clouds change according to solar activity.
Observations of Neptune’s clouds by the Hubble Telescope. (Photo = NASA, ESA, Erandi Chavez (UC Berkeley), Imke de Pater (UC Berkeley)) The research team photographed Neptune with the Keck Observatory and the Hubble Telescope in Hawaii, USA from 1994 to 2022, and the clouds were most active in 2002. Observations have been made and the clouds have decreased in 2007. This is related to solar activity with an 11-year cycle, and it is explained that when the sun emits strong ultraviolet rays, there are many clouds on Neptune about two years later. The research team said that Neptune’s atmosphere has a high methane content, and as solar ultraviolet rays reach it, a chemical reaction occurs, increasing the amount of clouds and reflecting these clouds, making Neptune brighter.
Afterwards, Neptune brightened again in 2015, and the clouds began to disappear in 2019, and in 2020 it is said to have dimmed to the lowest level among observations. The research team explained, “When Neptune was photographed by the Webb telescope last year, more clouds were observed by the Keck Observatory telescope.” This means that the sun’s ultraviolet activity is increasing and clouds are increasing again.
“It’s fascinating to be able to use telescopes from Earth to study the climate of a world 4.3 billion kilometers from Earth,” said Professor Pater. “It could help deepen our understanding of Neptune as well as exoplanets.” told
