At first glance, this image of Saturn looks as if it may very well be a shot from an old
Star Trek” episode, due to its barely grainy appearance and analog-esque glow. But this composite photo was taken on Oct. 22, 2023, by the Hubble Space Telescope — and most significantly, it captured a really interesting detail.
In case you look rigorously on the thick white inner band of Saturn’s rings, you may see shadowy appearances that nearly appear to be dirty fingerprints. These are Saturn’s mysterious ring spokes, transient features in regards to the size of Earth that appear to rotate together with the rings. But ultimately, scientists do not know what they’re.
The spokes are only visible for 2 or three rotations across the planet before they disappear, which suggests catching them in motion has historically been a difficult task; they were first spotted in 1981 by Voyager 2, nevertheless multiple times in the course of the Cassini mission, which orbited Saturn from 2004 to 2017. Now, Hubble is maintaining a tally of the bizarre feature as a part of the Outer Planets Atmospheres Legacy (OPAL) program, which monitors the weather on our solar system’s gas giants.
“The leading theory is that spokes are tied to Saturn’s powerful magnetic field, with some form of solar interaction with the magnetic field that provides you the spokes,” OPAL program lead scientist Amy Simon of NASA’s Goddard Space Flight Center said in a press release.
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Past Hubble images have shown that the spokes appear seasonally — Saturn’s seasons each last about seven years. “We’re heading towards Saturn equinox, once we’d expect maximum spoke activity, with higher frequency and darker spokes appearing over the subsequent few years,” said Simon.
That is because Saturn’s tilt on the equinox orients the planet and its rings in such a way that solar winds can collide with the planet’s magnetic field more forcefully, leading to more pronounced spokes. Well, if the leading theory in regards to the reason behind the spokes is correct, that’s.
Over time, scientists hope Hubble’s continued commentary of Saturn and its rings might help unravel the mystery of the spokes.