It is the realm of the giant planets : Jupiter, Saturn, Uranus and Neptune, which extends up to 30 times the distance between the Earth and the Sun. Unlike the rocky terrestrial planets like Earth and Mars that huddle close to the heat of the Sun (in the inner solar system), these distant worlds are composed mainly of cold gaseous soups of hydrogen, helium, ammonia, methane and other gases , around a compact and intensely hot center.
Hubble , the world’s most famous telescope, takes a long tour of the planets in the outer solar system each year, checking their turbulent atmospheres for changes in weather, storms, clouds and colors. And we already have the snapshots of the annual tour available. Like large thick balls of gas and ice, the colors and patterns on their surfaces are constantly changing, driven by dynamic forces that are not yet fully understood.
Jupiter
The image of Jupiter shows the tumultuous atmosphere of the giant planet. While the equator has drifted away from its traditional white or beige appearance for a few years, astronomers were surprised to find a more intense orange in recent Hubble images, when they expected the area to cloud again.
Saturn
The image of Saturn shows rapid and extreme color changes in the bands of the planet’s northern hemisphere, where we are now in early autumn. The bands have varied throughout the Hubble observations in both 2019 and 2020.
Uranus
The view of Uranus brings the planet’s bright north polar hood into the spotlight. It is spring in the Northern Hemisphere and increased ultraviolet radiation from the Sun appears to be causing the polar region to light up.
Neptune
Neptune’s dark spot, which was recently discovered to have changed course as it moved toward the equator, is visible in this Hubble image. Its characteristic blue color is the result of the absorption of red light by the methane-rich atmospheres of the planet s, combined with the same Rayleigh scattering effect that makes Earth’s sky blue.
Referencia: NASA, ESA, A. Simon (Goddard Space Flight Center), and M.H. Wong (University of California, Berkeley) and the OPAL team
