Starship Asterisk*

Is there an easy explanation I can tell my 7-year-old grandson explaining why the nebula is mostly 80% red but has a distinctive blue colored clock hand about at the 3 o'clock position? Here's what I know. The red is mostly hydrogen gas absorbing the red as absorbtion from the solar winds. The blue...

What little sky is visible looks very Earth-like.

This image is mirror reversed.

JohnD wrote: ↑Sun Jul 23, 2023 2:16 pm Regaining his self respect, [Harrison Ford] plays his actual age in the modern part, although he still wields a mean right uppercut!

Not as mean as his goddaughter’s.

Ann wrote: ↑Sun Jul 02, 2023 11:29 am Here you are. But I wasn't able to find Sirius.

The tail end of Canis Major is at the extreme upper left of the photo, so no, Sirius is not in the frame.

I’ve never seen M24 with this level of clarity before.

If the dots are accurate, and I assume they are, then they're a bit of a surprise to me. I thought the path would always look like a part of an ellipse, but the shapes are a bit different than that. Note how the path on the summer solstice, especially, seems to get nearly linear near the horizon. *...

You can get a nice yellow by programming red and green just right. (Although pure yellow emitters are now being employed to free up the other color emitters). But mixing red and green via dyes gives brown. There is no such thing as a brown light gel, because brown is a very low amplitude yellow. Pu...

“Twenty-First Century Regression,” unfortunately. I once met someone who actually believed that scientists had actually accidentally punched through the actual literal firmament, and water started pouring through. He had caught my attention because he was pointing at Jupiter and telling his partner ...

I’ve never seen a photo of M63 this deep before!

The photo even captures the surface features of the Moon.

orin stepanek wrote: ↑Wed May 03, 2023 6:26 pm If a Black hole lets no mater escape' what are
the jets? Is mater escaping with the jets?

Aside from Hawking radiation (which is negligible), no matter or light is escaping from the black hole itself. The jets are escaping from the accretion disc surrounding the black hole.

APOD Robot wrote: ↑Wed May 03, 2023 4:06 am Cen A is the fifth brightest galaxy on the sky ...

Let’s see...

1. Milky Way
2. Large Magellanic Cloud
3. Small Magellanic Cloud
4. M31
5. M33
6. Centaurus A
7. ...

Obviously, the Milky Way is not included in the description’s ranking.

Managed to see it from the Southern UK and get this 2 hour timelapse: [youtube]https://youtu.be/_9M3nIdcJVQ[/youtube] Unfortunately I'd had a couple beers so couldn't drive up to the moors to find a better vantage point. Glad I set up the camera though. You made the right decision, and you got a co...

APOD Robot wrote: ↑Tue Apr 25, 2023 4:06 am Our unusually active Sun may provide future opportunities to see the northern lights in southern skies.

What about southern lights from northern skies? Come to think of it, I don’t believe I’ve ever seen photos of the aurora australis.

APOD Robot wrote: ↑Mon Apr 17, 2023 4:07 am The red ELVES ring pictured had a radius of about 350 km and was captured in late March about 100 kilometers above Ancona, Italy.

I immediately noticed that the geometry doesn’t work out, so I checked the Wikipedia link. It says that the ring is 360 km in diameter, not radius.

Speaking of Judy Schmidt, has anyone heard from her lately?

I haven’t seen her around lately.

APOD Robot wrote: ↑Mon Mar 27, 2023 4:06 amThe featured image, taken after sunset late last month, looks directly south, ...

I get this configuration for February 27 at 12:30 a.m. GMT.

APOD Robot wrote: ↑Tue Feb 21, 2023 5:06 am The orange star just over the falls is Kochab. With the exception of a brief encounter with a black bear, ...

So, two bears in this description!

What used to be considered a hole in the sky is now known to astronomers as a dark molecular cloud. A bit of thought shows that it would be prohibitively improbable for it to be a hole in the sky, even if we didn’t have the infrared images. Such a hole would have to be a roughly conical wedge with ...

Do AIs know that “red” is relative, and that red dwarfs are more or less the color of incandescent light bulbs? Well, I guess not, if they’re learning from human artists. I have seen very, very few red or yellow stars depicted realistically by human space illustrators. I understand that some artisti...

But as a Color Commentator, I'm somewhat critical of the pink color of the center of the large spiral in Özsaraç's image. In RGB+Hα pictures of galaxies, like today's APOD, the pink color signals high level of hydrogen alpha and high levels of star formation. All the little pink dots that follow th...

A question. In the close-up of JD 3 there is a small totally green galaxy that's even smaller than JD 3 at the bottom right corner. Could this be an even younger galaxy and why is it green? Was it really green, or that it was red shifted to green because of its distance and it was really some other...

The most detailed periodic table I've yet found is the one from https://www.vertex42.com/ExcelTemplates/periodic-table-of-elements.html. There are both PDF and Excel format versions. Here's the color PDF - https://www.vertex42.com/Files/pdfs/2/periodic-table_color.pdf. Note that as of 2012, 114-unu...