Sky & Telescope illustration source: NASA / Hubble Space Telescope STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C.These images suggest how the ringed planet Saturn might will look when seen through a telescope with an aperture 4 inches (100 mm) in diameter (top) and through a larger instrument with an 8-inch aperture (bottom). The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations. NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Hubble Space Telescope is a project of international cooperation between NASA and ESA ( European Space Agency). In Saturn’s case, astronomers continue tracking shifting weather patterns and storms. OPAL is helping scientists understand the atmospheric dynamics and evolution of our solar system’s gas giant planets. This image is taken as part of the Outer Planets Atmospheres Legacy (OPAL) project. Two of Saturn’s icy moons are clearly visible in this exposure: Mimas at right, and Enceladus at the bottom. “However, NASA’s Cassini spacecraft measurements of tiny grains raining into Saturn’s atmosphere suggest the rings can only last for 300 million more years, which is one of the arguments for a young age of the ring system,” said team member Michael Wong of the University of California, Berkeley. Many astronomers agree that there is no satisfactory theory that explains how rings could have formed within just the past few hundred million years. But because the rings are so bright – like freshly fallen snow – a competing theory is that they may have formed during the age of the dinosaurs. Conventional wisdom is that they are as old as the planet, over 4 billion years. Just how and when the rings formed remains one of our solar system’s biggest mysteries. The rings are mostly made of pieces of ice, with sizes ranging from tiny grains to giant boulders. Hubble’s sharp view resolves the finely etched concentric ring structure. Conversely, the just-now-visible south pole has a blue hue, reflecting changes in Saturn’s winter hemisphere. “It’s amazing that even over a few years, we’re seeing seasonal changes on Saturn,” said lead investigator Amy Simon of NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Another theory is that the increased sunlight in the summer months is changing the amounts of photochemical haze produced. This may be due to heating from increased sunlight, which could either change the atmospheric circulation or perhaps remove ices from aerosols in the atmosphere. Hubble photographed a slight reddish haze over the northern hemisphere in this color composite. The ringed planet’s atmosphere is mostly hydrogen and helium with traces of ammonia, methane, water vapor, and hydrocarbons that give it a yellowish-brown color. The banding in the northern hemisphere remains pronounced as seen in Hubble’s 2019 observations, with several bands slightly changing color from year to year. These are transient features that appear to come and go with each yearly Hubble observation. Hubble found a number of small atmospheric storms. This new Saturn image was taken during summer in the planet’s northern hemisphere. Saturn is truly the lord of the rings in this latest snapshot from NASA’s Hubble Space Telescope, taken on July 4, 2020, when the opulent giant world was 839 million miles from Earth. Wong (University of California, Berkeley), and the OPAL Team Simon (Goddard Space Flight Center), M.H. Two of Saturn’s icy moons are clearly visible in this exposure: Mimas at right, and Enceladus at bottom. NASA’s Hubble Space Telescope captured this image of Saturn on July 4, 2020.
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