The NASA/ESA Hubble Space Telescope's Wide Field Camera 3 observed Saturn on 20 June 2019 as the planet made its closest approach to Earth this year, at approximately 1.36 billion kilometres away.
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| The NASA/ESA Hubble Space Telescope's Wide Field Camera 3 observed Saturn on 20 June 2019 as the planet made its closest approach to Earth this year, at approximately 1.36 billion kilometres away [Credit: NASA, ESA, A. Simon (Goddard Space Flight Center), and M.H. Wong (University of California, Berkeley)] |
Saturn hosts many recognisable features, most notably its trademark ring system, which is now tilted towards Earth. This gives us a magnificent view of its bright icy structure. Hubble resolves numerous ringlets and the fainter inner rings.
Dutch astronomer Christiaan Huygens first identified the rings in 1655 and thought they were a continuous disk encircling the planet, but we now know them to be composed of orbiting particles of ice and dust. Though all of the gas giants boast rings, Saturn's are the largest and most spectacular.
This new Hubble Space Telescope view of Saturn, taken in late June of 2019, reveals the giant planet's iconic rings.
Saturn's amber colors come from summer smog-like hazes, produced in photochemical reactions driven by
solar ultraviolet radiation. Below the haze lie clouds of ammonia ice crystals, as well as deeper, unseen
lower-level clouds of ammonium hydrosulfide and water. The planet's banded structure is caused by winds
and clouds at different altitudes. Hubble's Wide Field Camera 3 observed Saturn on June 20, 2019,
as the planet made its closest approach to Earth, at about 845 million miles away
[Credit: NASA's Goddard Space Flight Center]
Another intriguing feature is the long-lasting hexagon-shaped structure circling the planet's north pole. It is a mysterious six-sided pattern caused by a high-speed jetstream. The hexagon is so large that four Earths could fit inside its boundaries (there is no similar structure at Saturn's south pole).
Other features, however, are not as long-lasting. A large storm in the north polar region spotted by Hubble last year has disappeared. Smaller, convective storms, such as the one just above the centre of the planet's image, also come and go.
This Hubble time-lapse movie shows the orbits of some of Saturn's icy moons as they circle the planet over
an 18-hour period. The video is composed of 33 Hubble snapshots of the planet, taken June 19 to 20, 2019,
by the Wide Field Camera 3. The closer the moon is to Saturn, the faster it orbits, according to the
laws of gravity [Credit: NASA, ESA, A. Simon (Goddard Space Flight Center), M.H. Wong
(University of California, Berkeley), the OPAL Team and J. DePasquale (STScI)]
Saturn's appearance changes with its seasons, caused by the planet's 27-degree axial tilt. This image was taken during summer in the planet's northern hemisphere.
Source: ESA/Hubble Information Center [September 12, 2019]
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