Astro-image of the day: Lunar libration

[mckitterick]

This is so cool, something I've never seen before. You read about phenomena like libration (the Moon's wobble as it orbits the Earth), but this little .gif movie is new to me. This is a time-lapse of the phases of the Moon during one full orbit. Cool!

Click the image to see the story.

And no, it's not an optical illusion: The Moon does appear to get bigger and smaller during the month due to its elliptical orbit (not perfectly circular).

Best,
Chris

Comments

[jjgalahad.livejournal.com]

I . . . Can't . . . STOP . . . Staring . . . AT IT.

[mckitterick.livejournal.com]

I know! I considered posting two side-by-side images of it just for a bit of psychedelia.

[jjgalahad.livejournal.com]

Could you walk me through the HTML to repost this gif on my LJ? I'm a bit of a moron when it comes to such things but I very much want to share this one.

[jjgalahad.livejournal.com]

Never mind! I think I've got it. Thanks!

[mckitterick.livejournal.com]

Any time you want to see how someone does something on a Web page, you can simply click View Source in IE or similar commands in other browsers, then scan the code for the part you want (use a search on the phrases nearby).

[jjgalahad.livejournal.com]

*slaps forehead*

Thank you. I swear, I make things needlessly complicated when it comes to technology.

[mckitterick.livejournal.com]

Well, everyone has to learn that at some point. In my indroductory tech-writing course, I bet only one or two people per class know that before I show them.

[drasecretcampus.livejournal.com]

So the gravity stretches it bigger when it gets closer to the Earth? Turbulence as it goes round the bend?

My guess is the Moon stays the same size but its apparent size alters because of the distance. Isn't that an optical illusion? Perspective and Very Small / Far Away territory.

[mckitterick.livejournal.com]

Wouldn't that be something! Like Io or one of the other giant-plane moons. It would be quite

No, you're right - this is technically an optical illusion. What I meant is that the size of the Moon's image does get bigger and smaller in this .gif; it's not an illusion due to the phases changing.