Japetus

Japetus is so small – about eight hundred miles in diameter—that even in the lunar telescopes its disk is barely visible.

Rambles at starchamber.com » Blog Archive » Two faces of a moon 2007

So let me remind you that Cassini—who discovered Japetus in 1671—also observed that it was six times brighter on one side of its orbit than the other.

Rambles at starchamber.com » Blog Archive » Two faces of a moon 2007

Like a lot of people, I read those words years ago and thought to myself: what is the dang deal with Japetus?

Rambles at starchamber.com » Blog Archive » Two faces of a moon 2007

Names which a century earlier had been familiar only to astronomers and classical scholars were now part of every educated person's world picture; almost every day there would be news from Ganymede, Callisto, Io, Titan, Japetus - or even more obscure worlds like Carme, Pasipha-, Hyperion, Phoebe ...

2061 Odyssey Three Clarke, Arthur C. 1987

The great ellipse was perfectly symmetrical, straddling the equator of Japetus with its major axis pointing toward the poles; and it was so sharp-edged that it almost looked as if someone had carefully painted a huge white oval on the face of the little moon.

2001 A Space Odyssey Clarke, Arthur C. 1968

At the same time, he felt that he was moving upward, and for a fleeting instant he wondered if he had fallen right through Japetus and was now ascending from the other side.

2001 A Space Odyssey Clarke, Arthur C. 1968

Japetus was approaching so slowly that it scarcely seemed to move, and it was impossible to tell the exact moment when it made the subtle change from an astronomical body to a landscape, only fifty miles below.

2001 A Space Odyssey Clarke, Arthur C. 1968

Perhaps that monolith on Japetus was hollow; perhaps the "roof" was only an illusion, or some kind of diaphragm that had opened to let him through.

2001 A Space Odyssey Clarke, Arthur C. 1968

So let me remind you that Cassini - who discovered Japetus in 1671 - also observed that it was six times brighter on one side of its orbit than the other.

2001 A Space Odyssey Clarke, Arthur C. 1968

Not until the ship was only fifty thousand miles out, and Japetus was twice as large as Earth's familiar Moon, did he notice the tiny black dot at the exact center of the ellipse.

2001 A Space Odyssey Clarke, Arthur C. 1968