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Earlier this month, astronomers using the Spitzer Space Telescope discovered a vast ring around Saturn, already famous for its rings. For example, in March the Hubble Space Telescope snapped an amazing series of Saturn's moons transiting across the face of the planet:

Click the image to see the story and watch videos of this event.

Little Enceladus and Dione cross from the left just above the rings, Mimas is on the right, and the huge moon near the top is Titan (and its shadow). Titan is larger than the planet Mercury, and its smoggy atmosphere is orange because of methane and nitrogen reacting in the sunshine. The reason we can see the moons in this shot is that Saturn's rotational axis is tilted, like ours, so its rings are tilted edge-on to us as they are every 15 years (they're at their fattest 7 years from now). Because the orbits of Saturn's major satellites are in the same plane as its rings, those rings usually obscure our view of moon transits. To see them in motion, check out the videos.

Speaking of rings, here's that shot I promised you:

Click the image to see the story.

This newly discovered ring starts about 6 million kilometers out from Saturn and stretches to 12 million kilometers. How big is that? As wide as one billion Earths side-by-side. It's too dim to see from the surface of the Earth, but if you could, it would stretch across the sky twice the width of the Moon. Whoah. Mind you, Saturn itself is only a dot to the naked eye. Phoebe - one of Saturn's most-distant moons - orbits within this vast ring, and scientists theorize that the moon created it.

Speaking of scale, here's a nice comparison shot between Saturn and Earth:

Click the image to read all about Saturn and its moons.

Makes me think about ringworlds or Dyson spheres. This ginormous ring would be teeny and invisible compared to a ring around the Sun. Consider that for a moment.

Best,
Chris

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( 10 comments — Leave a comment )
siro_gravity
Oct. 23rd, 2009 06:19 pm (UTC)
WOOOOOOOW!!!!! I love astro porn!!!
That video was so fun to watch, I thought it was interesting how you could see the shadows of the moons before the moons actually moved in front of the planet.

I don't think I've ever seen or heard of that super-huge ring around saturn.

All very fun to look at and think about.
mckitterick
Oct. 23rd, 2009 06:23 pm (UTC)
No one had heard of it until now, because they just discovered it! That's what prompted this post. Wow-ness.
skyflame
Oct. 23rd, 2009 06:31 pm (UTC)
Something I haven't seen is that if the newly-found ring is in the same line as the original set of rings, or if it's at an angle. Saturn could have it's own mini-Kuiper belt!
will_couvillier
Oct. 23rd, 2009 06:36 pm (UTC)
"Consider that for a moment"

Stretches the brain like taffy. Not enough, however, to boggle, although that ring would make one fine & powerful solar collector if aimed the right way with interconnecting particles. Sounds like a story in there somewhere...
mckitterick
Oct. 24th, 2009 04:00 am (UTC)
Indeed!
saffronhare
Oct. 23rd, 2009 06:42 pm (UTC)
The scale and wonder of all this just incredible. Wow.
mckitterick
Oct. 24th, 2009 04:01 am (UTC)
I had to share.

And LOVE the icon!
skyflame
Oct. 23rd, 2009 07:14 pm (UTC)
I've been reading up on the Dawn mission this afternoon, the mission to investigate Ceres and Vesta, and there's a NASA journal updated every so often. In the most recent entry, there's lots of talk about orbits and trajectories and the like... and then the author comes up with this to end it:

P.S. The astronomical unit has been mentioned in these logs frequently enough that we will include that convenient unit of measurement from now on in the famously unimaginative concluding paragraph. It might appear redundant to present the distance from Earth both in astronomical units and in terms of how many times as far as the Sun it is. Isn’t that simply 2 different ways to describe exactly the same quantity? Well, no it is not; they are different, although they are close. An astronomical unit is the average distance between Earth and the Sun and hence does not change. The actual distance varies slightly throughout the year, so Earth’s distance from the Sun at any given time may not be precisely the average value of 1.00000000 AU (149,597,871 kilometers or 92,955,629 miles). This would be more apparent if your correspondent did not round off the numbers as dramatically. The details on that closing text are that Dawn is 1.50456971 AU (225,080,425 kilometers or 139,858,224 miles) from Earth. At the same time, Earth is 1.00222102 AU (149,928,510 kilometers or 93,161,078 miles) from the Sun, very close to the average, but not exactly equal to it. So Dawn is 1.50123544 times as far from Earth as the Sun is, given the distance to the Sun now. When rounded off, the distance in astronomical units and the distance in terms of how far the Sun is both come out to 1.50, but we see they are not really equal. Other times of the year, when the actual distance to the Sun is farther from the average, the difference will be apparent. As long as these secrets of the final paragraph are being revealed, here are the rest: the distance relative to the moon is rounded to the nearest multiple of 5, and the travel time for radio signals to the nearest minute. But just for this special occasion: Dawn is 556.865373 times as far as the moon right now, and radio signals take 25 minutes 1.574966 seconds. Approximately. Best regards to the Numerivores.
mckitterick
Oct. 24th, 2009 04:03 am (UTC)
It's pretty cool to consider all these little robot explorers we've sent out there, so far away that they have to act pretty much on their own in an emergency.
(Anonymous)
Aug. 24th, 2010 04:51 pm (UTC)
awesome!!!!!!!!!!!!!!!!! makes u start 2 think!!!
( 10 comments — Leave a comment )