Discover the cosmosEach day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Explanation:Don’t get spooked by Saturn’s ghostly spokes
Today we feature a nearly two-hour timelapse of Saturn and its rings looping forwards and backwards.
A day on Saturn is only 10 hours long, so two hours of observation covers quite a bit of its rotation.
If you look closely, a ghoulish shadow appears and disappears asSaturn’s B ringrotates.
Decades of observation with Voyager 2, Cassini, and Hubbleshow the appearance of Saturn’s spokes varies withthe planet’s seasons.
Like Earth, Saturn’sspin axisis tilted compared to the plane of its orbit around the Sun.
During Saturn’sequinox, the rings areless tiltedaway from the Sun and the planet receives more evenly distributed sunlight andsolar wind.
Although their origin is still uncertain, Saturn’s spokes may be shadows of and reflections off of dust and ice levitating above the rings caused byelectromagneticinteractions between the solar wind and the planet’s magnetic field.
Find dark skies and look up this August to witnessthe Perseid meteor showeruninhibited by the MoonTomorrow’s picture:the COSMOS