Astronomy Picture of the Day -- Neptune: Once Around

NASA ^ | July 14, 2011 | (see photo credit)

[SunkenCiv]

Explanation: Neptune rotates once on its axis in about 16 hours. So, spaced about 4 hours apart these 4 images of the solar system's most distant gas giant cover one Neptune day. Recorded by the Hubble Space Telescope in late June they combine exposures made with visible and near-infrared filters to show high-altitude clouds composed of methane ice crystals against the planet's normally blue cloud tops. Because Neptune's axis of rotation is tilted to its orbital plane by 29 degrees, compared to Earth's 23.5 degrees, Neptune experiences seasons analogous to Earth's. As early summer comes to Neptune's southern hemisphere and winter to the north, Hubble observations have shown cloud activity shifting to the northern hemisphere. In fact the progression of Neptune's seasons has come around once since its position was predicted by French mathematician Urbain Le Verrier and British mathematician John Couch Adams, and the planet was subsequently discovered by German astronomer Johann Galle on September 23, 1846. With an orbital period of approximately 165 years, this week on July 12, Neptune has been once around the Sun since its discovery date.

[TheOldLady]

We agree about Uranus, Carl Sagan, Halley, his comet, Bill Haley, and his Comets. We’z compatible, friend.

[fieldmarshaldj]

*groan*

Now that’s really bad. :-P

[fieldmarshaldj]

I just washed the ring out of it the other day.

[fieldmarshaldj]

Sagan had some weird-ass ways of pronouncing things. Like his, “Bullions and bullions of stars !” I thought he was talking about making soup or gold bars.

[fieldmarshaldj]

We must thank Sunken for his lovely picture of Uranus. It does look very shiny and clean.

[TheOldLady]

Come now, that’s one of his better ones. At least you can figure it out easily.

[TheOldLady]

It’s a laundry-day chore for you? Ew.

[TheOldLady]

Sagan was a pro-death, leftist, loony-tunes nutjob. I didn’t find that out until after I bought Cosmos, dang it.

[TheOldLady]

You’re right. Civ’ did a spectacular job cleaning up Uranus.

You realize that they’re going to pull this thread and zot the three of us, right?

[SunkenCiv]

If I get zotted, I’m blamin’ the two of ya.

Everyone else, however, will be thanking ya, and breathing a sigh of relief. ;’)

[SunkenCiv]

Apropos of nothing:

(attributed to Edgar Watson 'Ed' Howe)

[TheOldLady]

It would NOT be Free Republic without you, Civ’!

Of course, we can do without fieldmarshaldj, and even me, but never you.

[fieldmarshaldj]

Do they employ any other types at PBS ? Maybe you can unload your purchase on a like minded Sagan loon... :-P

[fieldmarshaldj]

After all, it only gets washed once in a blue moon. ;-D

[fieldmarshaldj]

Hey, like Laz, I’m here to give the joint atmosphere.

[TheOldLady]

Unload it? Sure! You interested?

[TheOldLady]

Grooooaaaan.

[TheOldLady]

Oh, very well. [sing-song] Free Republic wouldn’t be the same without you either, I suppose. ;-p

[fieldmarshaldj]

Not a chance. :-P