Saturn’s Hexagon
Saturn’s hexagon is a persisting hexagonal cloud pattern around the north pole of Saturn, located at about 78°N. The sides of the hexagon are about 13,800 km (8,600 mi) long, which is longer than the Earth’s diameter. It rotates with a period of 10h 39m 24s, the same period as Saturn’s radio emissions from its interior. However, the hexagon does not shift in longitude like other clouds in the visible atmosphere.

Saturn’s south pole does not have a hexagon, according to Hubble observations. But it does have a vortex, and there is also a vortex inside the northern hexagon.

Saturn’s polar hexagon discovery was made by the Voyager mission in 1981–82, and it was revisited since 2006 by the Cassini mission. Cassini was only able to take thermal infrared images of the hexagon, until it started to become visible by light in January 2009. Cassini also recently was able to take a video of the hexagonal weather pattern, while traveling at the same speed as the planet, therefore recording only the movement of the hexagon. After its discovery, and after it came back into sunlight, amateur astronomers managed to get a blurry view of the hexagon from Earth.

Credit: NASA/Cassini

Astronomy Picture of the Day: September 21st, 2014

Saturn at Equinox 


How would Saturn look if its ring plane pointed right at the Sun? Before August 2009, nobody knew. Every 15 years, as seen from Earth, Saturn’s rings point toward the Earth and appear to disappear. The disappearing rings are no longer a mystery — Saturn’s rings are known to be so thin and the Earth is so near the Sun that when the rings point toward the Sun, they also point nearly edge-on at the Earth. Fortunately, in this third millennium, humanity is advanced enough to have a spacecraft that can see the rings during equinox from the side. In August 2009, that Saturn-orbiting spacecraft, Cassini, was able to snap a series of unprecedented pictures of Saturn’s rings during equinox. A digital composite of 75 such images is shown above. The rings appear unusually dark, and a very thin ring shadow line can be made out on Saturn’s cloud-tops. Objects sticking out of the ring plane are brightly illuminated and cast long shadows. Inspection of these images is helping humanity to understand the specific sizes of Saturn’s ring particles and the general dynamics of orbital motion. This week, Earth undergoes an equinox.

Credit: Cassini Imaging TeamISSJPLESANASA

enuwey submitted:
Last year, while reading the Sailor Moon manga, I decided to paint mini portraits of all the Sailor Senshi and make them into stickers. It started with just Sailor Moon, Sailor Chibi-Moon, and Sailor Uranus.

…and then I decided to do all of the main Senshi, plus Tux, and the cats. So I did some drawing, and some painting, and I finished all of the main Senshi, and Tux.

…and then about a year later I decided that I needed to redo Saturn and Venus, and add a Sailor V to the lineup.

I really want to do the Moon Cats and the Asteroid Senshi next, but sadly those will have to wait because I ran out of paper. (and I’m waiting to find out if my order of these lovely stickers arrives on time for my next convention)

So, I hope you like these silly little things I painted. :)

I do! Those are fantastic. I especially love what you did with the long hair. And Mamoru looks so proud to have been included on a sticker. Thank you for sharing these!