Starship Asterisk*

About a year ago or so, I googled for images of star formation regions and came across the CTIO/NOAO/AURA/NSF image above. The picture came with no written information at all, so I didn't know what star formation region this was or what telescope had been used to take the picture. I decided I would ...

The Great Dark Horse Nebula in Ophiuchus

The Snake Nebula is in there. And the brightest blue star is Theta Ophiuchi, spectral class B2IV.

Ann

To me, these images were all somewhat uninspiring. However, I do think that the Saturn moons and rings image is fascinating. (My objection, as some of you may have guessed, is that it is black and white.)

Ann

I think it is interesting to have an occasional image of the Earth here, if only to remind us that the Earth is a part of the cosmos, too. However, I think that whenever possible, APOD pictures of the Earth should compare the Earth with other known planets. What about the Earth's volcanism compared ...

The third picture is looking extremely Earth-like to me. It's just like a sun-lit slope covered with soft, freshly fallen snow.

Ann

That's another globular cluster belonging to our galaxy, NGC 362.

Ann

Nice! I like the contrast between the somewhat loose blue dwarf galaxy and the compact yellow globular cluster. Of course, the globular cluster, 47 Tucanae, belongs to our own galaxy and not to the Small Magellanic Cloud, so the proximity between these two collections of stars is just a line of sigh...

That's a reflection nebula. Since blue light scatters much more efficiently than yellow and red light, reflection nebulae are usually blue. But not always, because it also depends on the color of the star whose light is being scattered. The white-looking star at bottom right of the picture of IC 460...

That's a beautiful and impressive image. It would be fun to know exactly how many background galaxies have had their shapes drawn into long filaments by the cluster's humongous gravity, and it would be fun to know which of the filaments actually "belong" to the same background galaxy.

Ann

Well, I've just done a general comet search, and it appears that there have been several green comets before. One comet whose colors seem to have been almost exactly the same as Comet McNaught's is Comet Lulin. Comet Lulin has even been described as "green comet Lulin". http://philosophyof...

Chris wrote: Ann wrote: Indeed, the color balance is off here. This is the first time ever that I have seen a dust tail look green. And the ion tail should be bluer. It does not appear to be off by very much. Do you calibrate your monitor? On my monitors (two, both calibrated) the dust trail appear...

Interesting, Owlice. Several other color pictures of this comet do indeed show that it has a remarkably green coma, a greenish dust tail and a not strikingly blue ion tail. It would seem that it is this particular comet's colors that are "off", not the photographers'. My apologies to Rich ...

Badsocref wrote: The ion tail should be slightly bluish and is (but only very slightly so). I do not know why the dust trail appears greenish, but it could have to do with our viewing angle. Indeed, the color balance is off here. This is the first time ever that I have seen a dust tail look green. A...

I think my favorite is the Wally Pacholka image, an amazing interplay between "heaven and Earth", so to speak. The way the clouds interact with the starry sky is fantastic. I love the "almost Milky Way-lit" observatory and ground, too, although I assume that this is a double expo...

I liked the picture a lot! What a nice take on Vermeer's The Astronomer , too. You changed his portrait of one man into a portrait of two persons, Robert Nemiroff and Jerry Bonnell, the creators of Astronomy Picture of the Day. It's a beautiful picture that reminds us of how long humanity has tried ...

Biddie67, thank you very much for your kind comment!

Ann

Definitely interesting.

I find it remarkable, however, that a planet which ought to have been considerably colder than the Earth had one of its polar regions covered in liquid water. Any thoughts?

Ann

Okay. Thanks, Chris.

Ann

I have heard that what is now the Mediterranean was once dry land where people lived and livestock grazed. Then, very suddenly, the Atlantic Ocean broke through the Sound of Gibraltar, and the land inside was flooded extremely quickly. This event may have lived in memory and given rise to stories ab...

Yes!!! I'm so glad that this splendid image was made Astronomy Picture of the Day!! Congratulations, Ronnie!

Ann

NGC 5746 is a nice-looking galaxy, to be sure. It has a very nice and striking shape. But to me it is a boring galaxy, because it is all monocolored: it is all yellow through and through, because its brown dustlane can be considered just another form of yellow, though a darkened one. There is no sta...

And that's what we are reduced to when it comes to pondering the question of extraterrestrial life - believing, thinking, guessing. Proving the existence of extraterrestrial life might well be hard, if that life doesn't look like we expect life to look, and if it exists in places where we have a har...

I can select only one? How will I be able to choose? :( M51 is extremely handsome in that image! Downright dashing! That galaxy sure knows how to put on the ritz, and all those pink rhinestones against that sky blue suit and the little yellow "brooch" in the middle holding the swirling sta...

Sorry, Antennae! http://www.newscientist.com/data/images/ns/cms/dn11509/dn11509-1_600.jpg I was going to vote for you. Really I was. You see, I have the greatest respect for people who would vote for that Saturn image, because I, too, think it is amazing that we humans have managed to send a spacecr...

By the way, since Gendler's (Hubble-based) image has a very different color balance than Gerber and Hager's image, which color balance is the best? In my opinion there can be no doubt that Gerber and Hager's color is better. I've said it before and I'm saying it again, the Hubble people can't do col...