Starship Asterisk*

Well, if we interpret color with our eyes, and our eyes never see green in any stars, I don't know what to say other than stars aren't green. And if that makes me stupid then I'll take stupid. Here's a picture of a star that ended up green. https://flic.kr/p/2iFw1Hk Here's another star that was gre...

Nice photo!
But, how does this Southern Cross work?
Do either of the "crossbars" point South?
Is the South Celestial Pole "visible" in this photo?
(Feeling blessed us people in Up Over have such a definite pole star)
Thanks for any response!

be nice to drag this little world into the goldilocks zone and let the ice melt! :mrgreen: My guess (hardly scientific); is that if Enceladus were brought close enough to the Sun to melt the ice, the gravity and atmosphere of such a small "moon" would not be enough to keep the water from ...

Ann,
Thank you very much for the "play by play"!
You went above and beyond answering my question!
I did get a couple of bad links, but that may be an effect of the nanny router here at work.

Picking chokecherries was a common activity in my childhood, which lead to chokecherry syrup on pancakes. :-D (Not to be confused with Choke Berries, a different plant) Chokecherries were sometimes used in making pemmican. (A friend once told me, "If you are offered some pemmican, refuse it!&q...

Kinda creepy looking, but also awesome!
What is the cluster of bright stars near the bright spot on the left (Jupiter) of the Milky Way?

Picking chokecherries was a common activity in my childhood, which lead to chokecherry syrup on pancakes. :-D (Not to be confused with Choke Berries, a different plant) Chokecherries were sometimes used in making pemmican. (A friend once told me, "If you are offered some pemmican, refuse it!&qu...

Based on email from James Norris, a leading authority and author on the sailing stones, the last sentence of the APOD text on the main NASA site has now been updated to read "It turns out that in winter thin floating ice sheets form in a rare ephemeral lake, and light winds push ice sections t...

"She's breakin' up on us Captain!"
-Engineering Officer Montgomery Scott

I am afraid I never heard of the red/green definition of dawn. An hour or so searching this morning got me no closer. I will check back later in hopes of a reference or link. Beautiful picture of the day! I'm afraid I'm not of further assistance in that regard. It may have been in the latter 1970's...

Pikov Andropov wrote: ↑Thu Apr 09, 2020 4:21 am Interesting concept, dark lighting. I am curious as to why the caption was so pseudo-scientific.

How about an article from an accredited electronics journal?

https://www.edn.com/zener-enhanced-dark ... -per-watt/

orin stepanek wrote: ↑Wed Apr 08, 2020 11:02 am It is hard to see the MW from aa position within a city! Actually; all these were taken outside the city!

I suspect the camera is more sensitive at "seeing" The Milky Way in "the city" than human eyes are...

Interesting concept, dark lighting. I am curious as to why the caption was so pseudo-scientific. It read more like a post from a politically-driven environmentalist blog than an explanation from a professional astronomer. I assume the grammatical errors and awkward writing style (clunky in places) ...

FYI: Military dawn is when you can tell the difference between a red cloth and a green cloth. The US Army had (has?) a small "booklet" with a sample of both cloths to aid commanders in determining when it is "dawn".

That's a beautiful picture. My compliments to the photographer. I especially like the zigzag lines you made. This explanation though got me to thinking. If the camera was truly at the north pole, then the circular pattern would be overhead, and now that the season is spring the midnight sun would b...

https://upload.wikimedia.org/wikipedia/commons/4/4b/TrohoidH1%2C25.gif The caption suggests what might make an interesting variation on these images. If one could, over the course of one night, get the camera to move a significant amount northward, say 10 degrees north, all the while otherwise keep...

We've had overcast skies that past several evenings.
Alas and alack!

My theory is that "barred galaxies" are illegally parked, and the Intergalactic Police have put a Parking Boot on them until they pay their fine.

https://en.wikipedia.org/wiki/Wheel_clamp

What is the width of this scene at the distance of the galactic center? Good question, but the answer is not easy, because time and space are compressed by the black hole, so while it may "look" to be 2^x furlongs wide, there may be an infinite number of furlongs, barleycorn lengths or ce...

All "eyes" are on today's APOD.
The Russians should launch a Spudnik probe for further invegetation.
I wonder if their dictater would risome to the occasion.

The spatial and temporal coherence of laser light goes beyond simply having the same wavelength. You can easily create light of a single wavelength with a filter, but that light won't be coherent. That also requires that the photons be in phase with each other. That's only possible if they have the...

[...] By the way, is laser light a sign wave with very high amplitude? [...] As neufer answered correctly, "NO!" LASER light is "coherent", all the photons are at the same [i.e. very close to the same] _frequency_. Each fundamental colour of light has its own frequency, or often...

Ann wrote: ↑Fri Mar 27, 2020 4:08 pm
It works for me. Have you tried again?

Ann

It worked later.
Thanks for responding!

Upvote to neufer for the obscure reference!
(I remember watching that show as a lad)

Okay, a "galaxy in a droplet" beats "galaxy in a marble" from Men in Black!