Starship Asterisk*

Fantastic find! Years ago, I worked on a stereo IMAX movie for science centers called "Magnificent Desolation: Walking on the Moon", and this image kicked my 3d moon brain into action and I had to make a minor adjustment. I made a few vertical "mesh warp" adjustments to better a...

Just a note to say that the Copper Canyon in Mexico is somewhat larger than the 'Grand Canyon' in Arizona, USA: "The combined length of the ravines makes Mexico’s Copper Canyon a whopping four times larger than the Grand Canyon in the United States. In some places, it’s even deeper than the Gra...

Just wondering - 1) What makes this BH so active in spitting out the jet-stream so long (distance), for so long (billions of years) ? Was there so much gas surrounding the BH that was "falling in" (quantity or type way different than other massive BH that are not spitting out such long an...

There is at least one other such crater with a double ring on Mercury crater Stoddart, see: https://www.flickr.com/photos/europeanspaceagency/53973209911/in/dateposted/ "The image reveals two ‘peak ring basins’, so-called due to their inner ring of peaks on an otherwise flattish floor. Vivaldi,...

"I think you've missed my point, which is just that there aren't very many fundamental natural laws, and we appear to understand most of them." Well, maybe, but how do you know "that there aren't very many fundamental natural laws", and what do you mean by "aren't very many&...

Modern science is perhaps a century old. And in that time, no major fundamental theories have been thrown out and replaced. Only modified. Dark energy is certainly in that category. We don't prove major things wrong anymore. Because we've mostly figured them out. I have little doubt that in a centu...

I think we know almost everything. Just a few holes left, and nothing that we currently know is going to be overturned... just tweaked as we home on the final truths. The Universe is simple. Stunningly simple, and governed by just a handful of rules. It makes me think of Conway's Game of Life. A si...

Lovely photograph. I have seen green aurora from Iceland, but sadly never red. And a beautiful Perseid meteor streak. I am somewhat annoyed, however, by photographs, often beautiful in the selves which people genuinely believe show meteor tracks, but which, to me, look like satellite trails. The ev...

Lovely photograph. I have seen green aurora from Iceland, but sadly never red. And a beautiful Perseid meteor streak. I am somewhat annoyed, however, by photographs, often beautiful in the selves which people genuinely believe show meteor tracks, but which, to me, look like satellite trails. The eve...

What a wonderful photograph. Interesting and informative explanation. However, one minor quibble, the cloud itself is composed of millions of tiny droplets of water and ice Well, yes, but clouds are tenuous things and contain approximately 1000 droplets per cubic centimetre. So a cubic kilometre of ...

Do planetary occultations help in calculating planetary orbits these days, or have we already got such precise knowledge that we don't need the measurements of exactly when there are occultations any more?

Thanks to Ann, yet again, for an interesting and informative post.

“The story so far:
In the beginning the Universe was created.
This has made a lot of people very angry and been widely regarded as a bad move.”

― Douglas Adams, The Restaurant at the End of the Universe, Hitch-Hiker's Guide to the Galaxy

(Sorry, couldn't resist. Have a nice day everyone)

Superb image, particularly the corona which extends further than in many other images.

Just HOW is this a "Wolf" moon? There are no wolves on the island where I live, and few in Europe, and anyway the animals couldn't give a F&^*&^ about it! It's beautiful picture of a full moon! Why bring in all the false folkways? JOhn Indeed. There seems to be a bit of a trend fo...

Confused by the illumination of so much of Ganymede's surface. I was assuming that it was illuminated by the Sun, but that would mean only half the surface would be lit, whereas clearly from the image much more than half appears to be lit. Is Ganymede illuminated by Jupiter, or is there some pother...

Confused by the illumination of so much of Ganymede's surface. I was assuming that it was illuminated by the Sun, but that would mean only half the surface would be lit, whereas clearly from the image much more than half appears to be lit. Is Ganymede illuminated by Jupiter, or is there some pother ...

... But I was disappointed at the caption: APOD Robot wrote: Colors in meteors usually originate from ionized chemical elements released as the meteor disintegrates, with blue-green typically originating from magnesium, calcium radiating violet, and nickel glowing green. Blue-green? Like this? ███ ...

"Humans and all Earth-based life are carbon-based, " Well, we are just as much a water-based life form: "In adult men, about 60% of their bodies are water. However, fat tissue does not have as much water as lean tissue. In adult women, fat makes up more of the body than men, so they h...

I love the 'nod' to the Hitch-Hiker's Guide to the Galaxy 'Total Perspective Vortex' with the notice "You are here"

Thanks folks, you put a smile on my face.

Clicking on the image to get a larger picture, there are some dust clouds and a pink nebula to the bottom left of the image. What are these?

Strictly speaking a 'Henge' is an enclosed earthwork comprising a dyke surrounded by a ditch. (https://www.english-heritage.org.uk/visit/inspire-me/what-is-a-henge/) However, due to the popularity of 'Stonehenge' in the UK (https://www.english-heritage.org.uk/visit/places/stonehenge/) and the unique...

I was wondering what the red clouds and blue halo indicate about the chemical composition of the nebula? I expect they are false colours to enhance the image, but it would be nice to know.

Thanks in advance of replies.

First time I've felt seasick viewing an APOD.

Great animation, though, I just like having the ecliptic horizontal-ish, or at least consistent.

I wonder how much water is bound up in living things? After all, animals are basically bags of water with some impurities and plant sap contains a high proportion of water.