DescriptionNeptune Cloud Cover Over Three Decades (2023-019).png
English: This sequence of Hubble Space Telescope images chronicles the waxing and waning of the amount of cloud cover on Neptune. This long set of observations shows that the number of clouds grows increasingly following a peak in the solar cycle – where the Sun's level of activity rhythmically rises and falls over an 11-year period.
The chemical changes are caused by photochemistry, which happens high in Neptune's upper atmosphere and takes time to form clouds.
In 1989, NASA's Voyager 2 spacecraft provided the first close-up images of linear, bright clouds, reminiscent of cirrus clouds on Earth, seen high in Neptune's atmosphere. They form above most of the methane in Neptune's atmosphere and reflect all colors of sunlight, which makes them white. Hubble picks up where the brief Voyager flyby left off by continually keeping an eye on the planet yearly.
NASA, ESA, Erandi Chavez (UC Berkeley), Imke de Pater (UC Berkeley)
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Author
Space Telescope Science Institute Office of Public Outreach
Image title
This sequence of Hubble Space Telescope images chronicles the waxing and waning of the amount of cloud cover on Neptune. This long set of observations shows that the number of clouds grows increasingly following a peak in the solar cycle– where the Sun’s level of activity rhythmically rises and falls over an 11-year period.The theory is that the increased ultraviolet radiation from the Sun, during its peak of activity, causes chemical changes deep in Neptune’s atmosphere. After a couple years this eventually percolates into the upper atmosphere to form clouds.In 1989, NASA’s Voyager 2 spacecraft provided the first close-up images of linear, bright clouds, reminiscent of cirrus clouds on Earth, seen high in Neptune’s atmosphere. They form above most of the methane in Neptune’s atmosphere and consequently are not blue, but reflect all colors of sunlight. Hubble picks up where the brief Voyager flyby left off by continually keeping an eye on the planet yearly.
Short title
Neptune Cloud Cover Over Three Decades
Credit/Provider
NASA, ESA, Erandi Chavez (UC Berkeley), Imke de Pater (UC Berkeley)