Video of Saturn Occulted by the Moon

The entire universe in blog form
Feb. 24 2014 11:15 AM

The Moon Ate Saturn!

Moon occults Saturn
Saturn, about to get et.

Photo by Colin Legg, from the video

On Feb. 22, 2014, the Moon ate Saturn.

Well, kinda. From our point of view here on Earth, the orbit of the Moon swept it directly in between us and Saturn, blocking the ringed planet from our view. This kind of event is called an occultation, and they’re pretty cool to behold.


That video was shot by photographer Colin Legg, who took it from Perth, Australia, just before sunrise. Legg has a fantastic eye for astrophotography; I’ve featured his work on the blog so many times I can’t even link to it all, so just go here and click around to get an eyeful.

Occultations are amazing. I’ve seen a few myself, and they’re always fun. While I wouldn’t say they’re rare as a class of events—there’s usually one or two a year visible from a given site—seeing the Moon pass in front of a bright planet doesn’t happen terribly often.

Phil Plait Phil Plait

Phil Plait writes Slate’s Bad Astronomy blog and is an astronomer, public speaker, science evangelizer, and author of Death From the Skies!  

That’s because the solar system isn’t as flat as you might think. Most of the planets orbit in the same plane, so that from the side the solar system does look pretty flat. Saturn’s orbit is tilted relative to Earth’s by about 2.5°, which is a fairly narrow angle. But the Moon is only about 0.5° in size in our sky, which is pretty small. Not only that, the Moon’s orbit is tilted to ours by a hair over 5°, so things have to align just so to get Saturn and the Moon together in the sky. Usually they miss each other by a few degrees.

But this time it worked out well for us—well, some of us. Those of us in the U.S. missed it because our part of the Earth was facing the wrong way when it happened. Happily for Legg, though, Australia was in the right position to catch it.

If you want to know what’s next for lunar occultations, you can go to Universe Today, which has compiled a list of 101 astronomical events for the year. I may try to catch the March 10/11 event where the Moon blocks the somewhat bright star Lambda Geminorum. That’ll be a kick to see with binoculars, and it happens at 8:30 or so at night in Boulder, Colo., so I won’t have to get up at crack o’dawn o’clock to see it.

I’ll add that there is actually a group dedicated to observing such things: IOTA, or the International Occultation Timing Association. While you may not have the bug that bad, they do have pretty good lists of stuff to keep your eyes open for. Give it a shot!

Tip o’ the lens cap to Maik Thomas.


Frame Game

Hard Knocks

I was hit by a teacher in an East Texas public school. It taught me nothing.

Chief Justice John Roberts Says $1,000 Can’t Buy Influence in Congress. Looks Like He’s Wrong.

After This Merger, One Company Could Control One-Third of the Planet's Beer Sales

Hidden Messages in Corporate Logos

If You’re Outraged by the NFL, Follow This Satirical Blowhard on Twitter

Sports Nut

Giving Up on Goodell

How the NFL lost the trust of its most loyal reporters.

How Can We Investigate Potential Dangers of Fracking Without Being Alarmist?

My Year as an Abortion Doula       

  News & Politics
Sept. 15 2014 8:56 PM The Benghazi Whistleblower Who Might Have Revealed a Massive Scandal on his Poetry Blog
Sept. 15 2014 7:27 PM Could IUDs Be the Next Great Weapon in the Battle Against Poverty?
Atlas Obscura
Sept. 16 2014 8:00 AM The Wall Street Bombing: Low-Tech Terrorism in Prohibition-era New York
  Double X
The XX Factor
Sept. 15 2014 3:31 PM My Year As an Abortion Doula
  Slate Plus
Tv Club
Sept. 15 2014 11:38 AM The Slate Doctor Who Podcast: Episode 4  A spoiler-filled discussion of "Listen."
Brow Beat
Sept. 15 2014 8:58 PM Lorde Does an Excellent Cover of Kanye West’s “Flashing Lights”
Future Tense
Sept. 16 2014 7:36 AM The Inspiration Drought Why our science fiction needs new dreams.
  Health & Science
Bad Astronomy
Sept. 16 2014 7:30 AM A Galaxy of Tatooines
Sports Nut
Sept. 15 2014 9:05 PM Giving Up on Goodell How the NFL lost the trust of its most loyal reporters.