The NASA-ESA Hubble Space Telescope is investigating a “fascinating magic trick of nature”.
Something unusual is happening in a new Hubble Space Telescope image of the picturesque ringed planet Saturn. The view is spectacular in itself, but if you zoom in on the left side of the rings you can see two dark, shadowy spots. These are “rays”.
These enigmatic rays appear and disappear with the seasons. Saturn knows four Seasonsbut it takes a long time to cross them, each season takes about seven years. The planet will approach the autumnal equinox in its northern hemisphere in early 2025, but it’s already entered what NASA calls “radiation season.” This is the perfect time for Hubble observations to study rays.
Saturn’s peculiar magnetic field
Hubble is a joint project between NASA and the European Space Agency. NASA has released a video accompanying Hubble’s new image. It contains sequences that the Rays orbiting Saturn.
Scientists have discovered the rays – which can appear bright or dark depending on the angle – thanks to the Voyager spaceship by NASA in the 1980s. “The cause of the jets, as well as their seasonal variability, has not yet been fully explained by planetary scientists,” NASA said in a statement Thursday.
Area circled in red highlights the dark pinpoint rays of Saturn’s rings – NASA, ESA and Amy Simon (NASA-GSFC); Image processing by Alyssa Pagan (STScI); red highlight by Amanda Kooser/CNET
There’s a probable explanation for these odd properties, and it’s about that Saturn’s magnetic field.
“Planetary magnetic fields interact with the solar wind and create an electrically charged environment,” says NASA (this is how we get our pretty auroras on Earth). “Scientists believe the rings’ smaller, dust-sized ice particles can also become charged, causing them to temporarily hover above the larger ice particles and rocks of the remaining rings.”
If this turns out to be true, the basic recipe for Saturn’s rays is: ice particles, varying magnetic field, solar wind and seasonal changes. Rays are expected more pronounced near the equinoxwhich will give scientists the opportunity to make more observations and gather data that explains what’s happening.
Other planets in the solar system (the gas giants) have rings, but scientists have not seen similar radii beyond Saturn. According to Amy Simon, senior planetary scientist at NASA, “It’s a fascinating magic trick of nature that we only see on Saturn, at least for now.”
CNET.com article adapted from CNET France