Starship Asterisk*

Besides molecular biosignatures , detecting generated light seems an obvious method of finding advanced civilizations. Since we have a giant telescope that detects IR , could it help find heat generation of an alien nature? Probably not campfires of alien neanderthals :no: but ET’s may need to stay ...

Are there any estimates of the mass or average density of the California Nebula, and the average density of its surrounding medium? The mass is probably that of several tens of Suns. The density is that of a very hard vacuum. And no doubt, the density of the surrounding medium is less dense still! ...

If ISS’s solar panels were as close to the sun as it appears, they’d be pumping out some juice. Parker’s don’t need to be that big most of the time.

But the AC would really need to be cranked up.

The moon is so photogenic. I love to image it this time of year as it rises further north. IMG_6614.JPG A friend was out with his new dog Sadie when he noticed last week's Moon-Venus in conjunction with a photobomber. Moon Venus and Byron.jpeg Unfortunately not all images portray the scene realistic...

Last nights Hunter's moon did have a side kick. Though our two side kicks where fast asleep after a day at the lake on a cool October day.

Mostly cloudy but a slight chance of sun Another cloud break to "C" it.

Averaging 100 stars per year, Andromeda seems pretty good at star formation . :thumb_up: Prototypical? :wink: Annette Ferguson of Astronomy Magazine wrote: So, on average, we expect that roughly six to seven new stars form in the Milky Way every year. While this might seem small, the star-formation...

Averaging 100 stars per year, Andromeda seems pretty good at star formation.

Prototypical?

Seems to be an eye, staring back at us. Or some advanced civilization’s version of Webb.

If so, I’ll take two small ones please. Equipped with their version of glasses.

Can birds see rainbows? Does knowing what causes rainbows make them better or not?

I mean us.

So, we live in a universe full of older and newer gravitational waves. Let’s call the idea – POND . :wink: There are little, old splashes and big, new splashes that we can measure . What happens when they run into each other? Constructive and destructive interference? Sounds like a gravity-type mech...

RobS wrote: ↑Sun Jun 18, 2023 8:20 am Aren't these just Rossby waves?

Could be some kind of an enigma.

Roses, rainbows and shadows. The color of a rose preceeded a particularly long-lived rainbow during last night's thunderstorm. Perfect to capture the last light of the day and the shadows it created.

The only way I can think to visualize a next dimension is to look at a tilted mirror and see it's reflection in 3 dimensions. Might need to use my red/blue glasses.
( Not reflected)

So, about those multiverses Ann mentioned. I have not read all of Tegmark's stuff, but I'm imagining the (or a) Level I multiverse in his hierarchy as a ridiculously large region of "normal" space-time (that is, exactly like the one we exist in) containing an infinite number of smaller re...

Milky Way over Bioluminscent Border. Pay attention, people, because this is a sight that you will not find anywhere else in the Universe. Well, the Milky Way will look very much the same from any nearby exoplanet - hey, Proxima Centauri b and d - But the Bioluminescent Border? Forget it. Oh, I expe...

Two amazing things from this APOD are: 1. From the Wikipedia link: All adult tardigrades of the same species have the same number of cells (see eutely). Some species have as many as 40,000 cells in each adult, while others have far fewer.[22][23] Only 40000 cells (or less), and yet they are still s...

Makes me wonder what would a solar granule look like if viewed horizontally.

Flat with ripples?

When a viewer on Earth observes a total solar or lunar eclipse, both spheres appear to be exactly the same size. We know that the sun is much larger than the moon but is much, much farther in distance from the Earth than the moon. What are the odds that the positioning of the sun and moon in the sk...

Early astronomers paved the way looking at these dark patches. Their lives as groundbreakers had plenty of potholes to fill.

A bit longer discussion of this galaxy goes into a bit more detail. About 30 minutes in runs a perspective animation off of a credited Geck image.

Odd that bright star was once thought too bright for Hubble

And then there are isochrones - though I can't quite understand why I never see these isochrones plotted ON TOP of the standard H-R diagram. Is it because the metallicity needs to be the same? : https://upload.wikimedia.org/wikipedia/commons/9/93/Isochrones_of_several_ages.png That top (blue) isoch...

Personally I doubt that Gamma Musca is 68 million years old. I'd guess it is between 15 and 20 million years old, like Alpha and Beta. Admittedly it is nevertheless possible that Gamma Musca belongs to an earlier generation of stars than Alpha and Beta. Ann You could be right. How are these stellar...

This is the second day in a row that the "Discuss" link has been absent from the link strip below the text on the main APOD page. The "Discuss" link is always of the form: https://asterisk.apod.com/discuss_apod.php?date=YYMMDD For example, today's link is: https://asterisk.apod....

Can't you see? It's obviously the Pleiades! :lol2: Ann Sometimes it's hard to know what a photo can be made to realize. IMG_6229 (3).JPG When I was trying to photograph Jupiter and Venus from inside our house, an out-of-focus image seemed to contain unexpected detail of Jupiter. IMG_6219 (2).JPG Th...