Astronomy Picture of the Day 5-18-02

NASA ^ | 5-18-02 | Robert Nemiroff and Jerry Bonnell

[petuniasevan]

Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2002 May 18

Andromeda Island Universe
Credit & Copyright: Robert Gendler

Explanation: How far can you see? The most distant object easily visible to the unaided eye is M31, the great Andromeda Galaxy some two million light-years away. Without a telescope, even this immense spiral galaxy appears as an unremarkable, faint, nebulous cloud in the constellation Andromeda. But a bright yellow nucleus, dark winding dust lanes, gorgeous blue spiral arms and star clusters are recorded in this stunning telescopic digital mosaic of the nearby island universe. While even casual skygazers are now inspired by the knowledge that there are many distant galaxies like M31, astronomers seriously debated this fundamental concept only 80 years ago. Were these "spiral nebulae" simply outlying components of our own Milky Way Galaxy or were they instead "island universes" -- distant systems of stars comparable to the Milky Way itself? This question was central to the famous Shapley-Curtis debate of 1920, which was later resolved by observations of M31 in favor of Andromeda, island universe.

[petuniasevan]

As a child I lived within sight (if it wasn't smoggy) of Mount Wilson. Near its summit is the famed 100-inch Hooker telescope, where Edwin Hubble's hard work and long nights culminated in the proof that was needed - spectrograms and photos of M31 that revealed it to be no nebula but another galaxy.

It's not really a stretch, then, to say that Hubble discovered the universe from Mount Wilson 80 years ago. And his namesake telescope continues to reveal it in ever greater detail. I think he would have felt honored.

Get on the APOD PING list!

[petuniasevan]

APOD PING!

[petuniasevan]

I'm going to make a special request: I know some of you know a lot about astronomy, and others don't.
If you're in the latter group, or even in the former, here's a good site to visit. You'll learn about common misconceptions concerning all aspects of astronomy. It's also a good source of info to refute the tinfoil ("Apollo was a fake!") crowd.

Here's the site: Phil Plait's Bad Astronomy

[sleavelessinseattle]

Isn't Andromeda the Galaxy that the Milky Way is eventually going to collide with? My poor brain may have dropped a stitch but I try to visualize us all making an intergalactic journey when I watch too much network news...Keeps me from chewing the scenery in my apt;-D

[2Trievers]

Thanks 'tunia! &;-)

To behold the wandering Moon,
Riding near her highest noon,
Like one that has been led astray
Through the heav'n's wide pathless way.

-John Milton (1608-1674)

[petuniasevan]

As with many galaxy clusters, our Local Cluster has had and will have galaxies "colliding" (merging, really).
But don't wait up for the event - it's scheduled for about 5 billion years from now.

Here's a LINK to a description.

[petuniasevan]

Good find!

Here's a Shakespearean quote I love:

Now entertain conjecture of a time
When creeping murmur and the poring dark
Fills the wide vessel of the universe.

---Henry V, Prologue

[martin_fierro]

Bears a striking resemblance to a galaxy long ago and far, far away. <|:)~

[RightWhale]

Even with the sky as bad as it has gotten, M31 is still visible, barely, to the naked eye even when the Milky Way is washed out and stars dimmer than mag 4 are invisible. That's funny when you think we are inside the Milky Way and M31 is a million lightyears away. It's easy to spot once you have the route marked out starting from the Great Square of Pegasus.

[2Trievers]

Your Shakspeare quote is one of my faves ... there's another ...

Auguries of Innocence

To see a World in a Grain of Sand
And a Heaven in a Wild Flower,
Hold Infinity in the palm of your hand
And Eternity in an hour.

-William Blake (1709-1784)

[RightWhale]

Isn't Andromeda the Galaxy that the Milky Way is eventually going to collide with?

Last night Art Bell interviewed that famous cosmologist who is working on the brane theory, I forget his name, maybe he's not quite famous yet. He said that gravity is pulling the Milky Way and Andromeda together and eventually they will merge. I don't know if that is entirely accurate, but M31 is definitely coming our way.

[sleavelessinseattle]

Thanks RW...I just think its amazing that structures that old are still bouncing around like a set of billiard balls after the Big Break! Its important for people like me, who take all the apparent evil in the world today seriously, to remember that Earth is just a beautiful jewel in an infinity of possible worlds...Someplace, someone's going to get it right...I'm betting ALLAH will not be on the menu, there, though!

[petuniasevan]

million light-years away

Actually, about 2.2 million light-years.

[LibWhacker]

Here's one of my favorite pics of Andromeda -- by an amateur with a relatively small scope.
Here in the suburbs of Sacramento, it's not visible with the naked eye (or is it just my aging
eyes?) but you can easily see it with binoculars.

[petuniasevan]

No, it's probably not you. Sacto's urban skyglow washes out the sky most of the way to Chico (I used to live there).

[TxBec]

being that I just woke up, at first I thought you said cosmetologist.. I wondered what made her an expert LOL. sorry.

[aomagrat]

Behold!

[RightWhale]

Thanks for the clarification! 1 million lightyears seems far, but 2.2 million lightyears is really, really far. The kids in the back seat get restless on long trips, but they might need psychoanalysis both before and after the trip to M31.

[~EagleNebula~]

The pic was great, and thanks for the added dividend of the sweet words!!!

[Michael Barnes]

Beautiful photo

..Just take astep back and think about ALL the exploration there is in that galaxy alone. And we haven't even cratched the surface of our own...hell, we don't even have a valid "picture" of our own.