The scale of Saturn

The entire universe in blog form
Dec. 19 2011 10:45 AM

The scale of Saturn

With the Cassini spacecraft orbiting Saturn and making frequent fly-bys of all the weird moons there, it's easy to post one incredible close-up after another. But sometimes, you have to take a step back and get some context, see the bigger picture.

Cassini can do that, too. And when it does, the beauty and scale of the Saturn system is simply breathtaking:

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

[Click to encronosate.]

This image shows, of course, the ringed planet itself, with the rings seen edge-on and their shadow cast across the planet's southern hemisphere cloud tops. But look to the left, just below the rings; see that half-lit disk? That's Enceladus, an icy moon of Saturn. It's about 500 km (310 miles) across, which may start to give you an idea of how much area this picture covers. Even though it's as big as my home state of Colorado, it's positively dwarfed by the looming presence of Saturn behind it... and we're not even seeing very much of the planet here! Saturn is over 120,000 km (75,000 miles) across, nine times the diameter of Earth.

Saturn is big.

To pound this home, look even farther to the left of Enceladus. See that black speck? I've enlarged the picture and annotated it here; the arrow points to Epimetheus, a lumpy gray potato moon of Saturn. It's about 113 km (70 miles) long. That's small for a moon, perhaps, but on a human scale it's a huge rock, more than ten times the height of Mt. Everest.

Yet it's a speck in this picture, easily missed if you didn't know it was there. But I guess that's not surprising; Cassini was 1.2 million km from Saturn when it took this shot, three times the distance from the Earth to the Moon!

Sometimes people ask me, what's the one thing you wish people understood better about the Universe? And if I had to pick just one only, it would be this: scale.

The Universe is huge, and we've barely dipped our toes into it.

Image credit: NASA/JPL-Caltech/Space Science Institute. Tip o' the meterstick to Carolyn Porco.



Related posts:


TODAY IN SLATE

Foreigners

The World’s Politest Protesters

The Occupy Central demonstrators are courteous. That’s actually what makes them so dangerous.

The Religious Right Is Not Happy With Republicans  

The XX Factor
Oct. 1 2014 4:58 PM The Religious Right Is Not Happy With Republicans  

The One Fact About Ebola That Should Calm You: It Spreads Slowly

The Feds Have Declared War on New Privacy Measures From Apple and Google

These “Dark” Lego Masterpieces Are Delightful and Evocative

Crime

Operation Backbone

How White Boy Rick, a legendary Detroit cocaine dealer, helped the FBI uncover brazen police corruption.

Politics

Talking White

Black people’s disdain for “proper English” and academic achievement is a myth.

Europe’s Next Digital Commissioner Thinks Keeping Nude Celebrity Photos in the Cloud Is “Stupid”

Piper Kerman on Why She Dressed Like a Hitchcock Heroine for Her Prison Sentencing

  News & Politics
Politics
Oct. 1 2014 7:26 PM Talking White Black people’s disdain for “proper English” and academic achievement is a myth.
  Business
Moneybox
Oct. 1 2014 2:16 PM Wall Street Tackles Chat Services, Shies Away From Diversity Issues 
  Life
Outward
Oct. 1 2014 6:02 PM Facebook Relaxes Its “Real Name” Policy; Drag Queens Celebrate
  Double X
The XX Factor
Oct. 1 2014 5:11 PM Celebrity Feminist Identification Has Reached Peak Meaninglessness
  Slate Plus
Behind the Scenes
Oct. 1 2014 3:24 PM Revelry (and Business) at Mohonk Photos and highlights from Slate’s annual retreat.
  Arts
Brow Beat
Oct. 1 2014 6:39 PM Spoiler Special: Transparent
  Technology
Future Tense
Oct. 1 2014 6:59 PM EU’s Next Digital Commissioner Thinks Keeping Nude Celeb Photos in the Cloud Is “Stupid”
  Health & Science
Science
Oct. 1 2014 4:03 PM Does the Earth Really Have a “Hum”? Yes, but probably not the one you’re thinking.
  Sports
Sports Nut
Oct. 1 2014 5:19 PM Bunt-a-Palooza! How bad was the Kansas City Royals’ bunt-all-the-time strategy in the American League wild-card game?