Amira Shehata Saturday, August 26, 2023 12:00 AM A study on Big spot on the planet NeptuneUsing data from the European Space Agency’s Very Large Telescope (VLT), scientists have observed a large dark spot on Neptune about 6,200 miles (10,000 km) in diameter.
According to the British newspaper “Daily Mail”, this large void contains a smaller bright spot next to it, and scientists are still not sure how it was formed.
“We know that these dark spots are anticyclonic vortices, just like Jupiter’s Great Red Spot, but how and why they form is not known,” said Professor Patrick Irwin, a professor at the University of Oxford and lead investigator on the study.
Neptune’s dark spot was first spotted by NASA’s Voyager 2 spacecraft in 1989, however, it is not a permanent feature and disappears every few years, making it difficult to observe in sufficient detail.
In 2018, NASA’s Hubble Space Telescope detected the dark spot again, and Professor Irwin said: “The Hubble Space Telescope has seen several dark spots since Voyager 2 GDS.”
These patches seem to form randomly every few years at mid-northern or southern latitudes and then drift toward the equator, finally disappearing after one Earth year or so.
In this new study, Professor Irwin and his team worked to study Earth’s dark spot for the first time. The VLT is equipped with a multi-unit spectroscopic detector, which splits the sunlight reflected from Neptune into its component colors and wavelengths.
This allowed the team to study the site in more detail than ever before.
Professor Irwin said: “I am very happy to have not only been able to detect the first dark spot from Earth, but also to record a reflection spectrum of such a feature for the first time.”
Different wavelengths probe for different depths in Neptune’s atmosphere, which means the spectrograph can infer the size and height of the dark spot, as well as its chemical composition.
The new observations rule out the possibility that the dark spots are caused by cloud removal. Instead, the researchers believe that the dark spots are likely the result of ice and haze mixing in the atmosphere, causing air molecules to darken.
These rare clouds explain the presence of the bright spot next to the larger dark spot, and the team hopes that the results will show the capabilities of ground telescopes.
