Things

Sebastian Flyte: Home and Abroad

Wed, 22 May 2013 00:33:03 +0100

Sebastian Flyte: Home and Abroad

we-are-star-stuff: If Earth Had a Ring Like Saturn Our planet...

Wed, 22 May 2013 00:02:45 +0100

If Earth Had a Ring Like Saturn

Our planet is lucky enough to have a large moon orbiting not too far away, which makes for very pretty moonlit nights. But for spectacular skies it might almost be worth trading in our moon for a ring like Saturn’s.

In fact, the earth did once have a ring - as part of the formation of our moon, ironically enough. When the planet Thea crashed into the earth, a titanic amount of material was blown into space. This went into orbit around the earth, forming a ring until it all eventually coalesced into our present-day satellite. This only happened because the material was orbiting outside of earth’s Roche limit.

In 1848, the French mathematician Edouard Roche calculated that if a large satellite were to approach too closely to a planet, it would be torn apart by the planet’s gravitational forces. This happens because the gravitational attraction of a planet on a moon is not equal. The planet pulls more on the side of the moon closest to it and less on the side further away. If the moon gets too close, this unequal pull can become great enough to tear the moon apart. Every planet has what is called a Roche limit.

Some astronomers believe that Saturn’s rings are material that was unable to form into a moon because it lies within the planet’s Roche limit. The gravitational pull of Saturn prevents particles from clumping together to form a moon. Another idea popular among scientists suggests that during the time when Saturn was first forming, it had one or more moons just outside its Roche limit. The bigger a planet is, the more gravity it has. And the more gravity it has, the bigger its Roche limit is. So as Saturn grew larger, its Roche limit grew, too. The limit soon moved past the inner moons and these moons soon broke apart. The remnants of the destroyed moons eventually formed the magnificent rings we see today. There may still be large pieces of these ancient moons within the rings. They would be much smaller than their ancestors but a thousand times larger than a typical ring particle. Another theory suggests that a few hundred million years ago - at a time when the early ancestors of the dinosaurs were roaming Earth - Saturn may have had no rings at all. The rings formed when one or more small moons wandered too close to Saturn. When they got within the Roche limit, Saturn’s gravity ripped them apart. After millions of years of bumping against one another, the pieces of moon were ground into the tiny particles that form the rings today.

If we had rings in the same proportion to our planet that Saturn’s are to it, it is pretty easy to figure out what they would like like from different places on the earth. From the equator the rings would be passing directly overhead. Since you’d be looking in the same plane as the rings, all you would see is a bright line arching from horizon to horizon. Here is what the rings might look like from Quito, Ecuador:

If we travel just a little further north to Guatemala, the rings begin to spread across the sky. The earthlight illuminating the dark side of the moon is many times brighter than we are accustomed to, due to the increased sunlight being reflected from the rings.

From Washington, DC (at 38° latitude), the rings begin to sink below the horizon, though they would still be an awe-inspiring sight as they dominate the sky both day and night.

At the Arctic Circle, the rings barely reach above the horizon. Seen here from Nome, Alaska, the brilliant rings illuminate the barren landscape scarcely more than a full moon would. Unlike the sun or moon, however, the rings neither rise nor set… they are always visible, day or night, always in exactly the same place.

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Tue, 21 May 2013 21:51:39 +0100

meereeneseknot: Loras Tyrell and the Worst Party Ever

Tue, 21 May 2013 21:48:06 +0100

meereeneseknot:

Loras Tyrell and the Worst Party Ever

London 1926 (x)

Tue, 21 May 2013 21:32:51 +0100

London 1926 (x)

teflongrl: I always wear thermals.Ah, you’re probably fine...

Tue, 21 May 2013 21:31:15 +0100

teflongrl:

I always wear thermals.
Ah, you’re probably fine then.

game-of-style: yoly138: Sansa & Tyrion (Game of thrones...

Tue, 21 May 2013 21:12:06 +0100

game-of-style:

yoly138:

Sansa & Tyrion (Game of thrones 3x08 - “Second sons”)

free-parking: Vintage National Geographic images, via Female...

Tue, 21 May 2013 20:30:24 +0100

free-parking:

Vintage National Geographic images, via

Female beluga whale in Cunningham Inlet, Canada, 1994

Prekestolen over Lyse Fjord in Norway, 1957

Macaws in the Peruvian rain forest, 1994

Castelo de Pena near Sintra, Portugal, 1965

Solar eclipse, 1970

The Royal Danish Ballet, 1974

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Tue, 21 May 2013 17:31:26 +0100

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Mon, 20 May 2013 23:12:41 +0100

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Mon, 20 May 2013 22:16:00 +0100

mediamattersforamerica: Some people in the media seemed to be...

Mon, 20 May 2013 21:20:07 +0100

mediamattersforamerica:

Some people in the media seemed to be having trouble determining what counts as Watergate and what does not, so we made a handy flow chart!

lorienscribe: finduisas: vielzuvielliebeandermusik: Back on...

Mon, 20 May 2013 21:16:33 +0100

lorienscribe:

finduisas:

vielzuvielliebeandermusik:

Back on set for our last Hobbit pick ups. Our last ever Tolkien pick ups, in fact. It’s going to be an intense few weeks, but we’re looking forward to shooting some powerful scenes with our great cast. Our next blog is coming soon!

x

YAAY

Hee! :) And it was kind of amusing and sad to see the first comment asking about the Silmarillion. (although that other comment about the Silmarillion not being a real book. Really, guys? ;_; Then it’s an awesome non-book!)

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Mon, 20 May 2013 21:13:56 +0100

flavorpill: The Gay Bechdel Test: Why Hollywood Needs to Expand...

Mon, 20 May 2013 21:06:06 +0100

flavorpill:

The Gay Bechdel Test: Why Hollywood Needs to Expand Its Representation of LGBT Characters

The Gay Test (which, regrettably, I will not call “The Coates Test” following Alison Bechdel’s lead), would have similarly few requirements, but they’re particularly tough to beat: to pass, a film must include two gay characters who interact in some way, do not offer sassy advice to the protagonist, and are not dead by the end credits.

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Mon, 20 May 2013 20:30:10 +0100

She had often daydreamed of how she would dance at her wedding,...

Mon, 20 May 2013 18:05:25 +0100

She had often daydreamed of how she would dance at her wedding, with every eye upon her and her handsome lord. In her dreams they had all been smiling.

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Mon, 20 May 2013 15:00:38 +0100

mistersnurb: are you sure I have no idea why she’s so...

Mon, 20 May 2013 14:30:11 +0100

mistersnurb:

are you sure

I have no idea why she’s so popular, her voice is like nails on a blackboard.

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Mon, 20 May 2013 12:47:59 +0100