Cassini takes home video of Saturn's aurora

The entire universe in blog form
Nov. 24 2009 3:28 PM

Cassini takes home video of Saturn's aurora

Cassini keeps amazing me, even when I start to think I'm getting used to incredible images beamed back from Saturn.

But this is new: it took several images of Saturn's aurora, and strung them together to make a video! Here's a still frame:

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!  

Advertisement

cassini_aurora_image

The outline of Saturn is there, along with some latitude lines for reference (the bright thin wedge is the daylit side of the planet itself). You can see stars blurred in the background, with the aurora the orangey glow rising about the Saturnian cloud deck. This frame is cool, but for frak's sake go watch the video! It's mesmerizing. I'd put it here, but it's 3 Mb and that would destroy the Hive Overmind servers.

The images put together to create the animation were taken over four days. Interestingly (well, to me anyway) these images were taken in visible light; we already know from Hubble observations that Saturn's aurorae are bright in UV.

These northern lights on Saturn are formed in pretty much the same way they are on Earth: particles in the Sun's solar wind get captured in the magnetic field of the planet, and are swept to the poles where they slam into molecules in the atmosphere, lighting it up (literally) like a neon sign. The details are far more complicated, of course, but that's the basic picture. The images from Cassini don't show color, which is too bad: the color of the glow can tell you what chemical elements are in the atmosphere, since different atoms emit at different wavelengths. Still, there is much to be learned about Saturn's magnetic field from images like these.

And may I add: wow. Aurorae, from a billion kilometers away. Incredible!

TODAY IN SLATE

Medical Examiner

Here’s Where We Stand With Ebola

Even experienced international disaster responders are shocked at how bad it’s gotten.

It’s Legal for Obama to Bomb Syria Because He Says It Is

Divestment Is Fine but Mostly Symbolic. There’s a Better Way for Universities to Fight Climate Change.

I Stand With Emma Watson on Women’s Rights

Even though I know I’m going to get flak for it.

It Is Very Stupid to Compare Hope Solo to Ray Rice

Building a Better Workplace

In Defense of HR

Startups and small businesses shouldn’t skip over a human resources department.

Why Is This Mother in Prison for Helping Her Daughter Get an Abortion?

How Ted Cruz and Scott Brown Misunderstand What It Means to Be an American Citizen

  News & Politics
Politics
Sept. 23 2014 12:43 PM Occupy Wall Street How can Hillary Clinton be both a limousine liberal and a Saul Alinsky radical?
  Business
Moneybox
Sept. 23 2014 2:08 PM Home Depot’s Former Head of Security Had a Legacy of Sabotage
  Life
Outward
Sept. 23 2014 1:57 PM Would A Second Sarkozy Presidency End Marriage Equality in France?
  Double X
The XX Factor
Sept. 23 2014 2:32 PM Politico Asks: Why Is Gabby Giffords So “Ruthless” on Gun Control?
  Slate Plus
Political Gabfest
Sept. 23 2014 3:04 PM Chicago Gabfest How to get your tickets before anyone else.
  Arts
Brow Beat
Sept. 23 2014 2:31 PM 3 Simpsons Showrunners Reflect on New Fans and the “Classic Era” Myth
  Technology
Future Tense
Sept. 23 2014 1:50 PM Oh, the Futility! Frogs Try to Catch Worms off of an iPhone Video.
  Health & Science
Science
Sept. 23 2014 1:38 PM Why Is Fall Red in America but Yellow in Europe? A possible explanation, 35 million years in the making.
  Sports
Sports Nut
Sept. 18 2014 11:42 AM Grandmaster Clash One of the most amazing feats in chess history just happened, and no one noticed.