Starship Asterisk*

it would take a logarithmic scale to map the distances of every labelled thing in this APOD. The same goes for their lifetimes; those are like this: Aurora < Norwegian Sea < Big Dipper Stars < Mars, Pleiades, Milky Way, Andromeda 100 microyears < 10 megayears < 1 gigayear < 10 gigayears

Ann wrote: ↑Mon Dec 11, 2023 7:07 am Bright day 25 November 2023.jpg

Ann

nightification gamma .4 for the red chammel, .2 for the green channel, .1 for the blue channel

let me try it the other way round, to photoshop a daytime scene

into a nightish-feeling one

The Sun may be undergoing minimums and maximums (which is caused by its magnetism), but it still darn quiet for a star of its class! https://www.syfy.com/sites/syfy/files/styles/scale_600/public/sun_brightness_vs_star.jpg Ann what are the "365 solar-type stars"? Are they the same mass and...

offtopic about colourful scenes at night I challenge everybody to solve this mystery. If you zoom in this APOD and see just the bridge, the water and the trees, why do you still feel that it is night? It has to do with the quality of the light. Is the light "evenly distributed", as it is ...

The Sun may be undergoing minimums and maximums (which is caused by its magnetism), but it still darn quiet for a star of its class! https://www.syfy.com/sites/syfy/files/styles/scale_600/public/sun_brightness_vs_star.jpg Phil Plait of SYFY wrote: Astronomers have determined that, on average, the S...

offtopic about colourful scenes at night

I challenge everybody to solve this mystery.
If you zoom in this APOD and see just the bridge, the water and the trees, why do you still feel that it is night?

I hope when they make the 3d map of all the Euclids's galaxies up to redshift of 2,
they present it in an online 3d model, able to wobble slightly at user's command.

I don't mean a side view of a galaxy made up by some AI. I mean a little wobble to let the user feel the depth

that is a good news. Of course it depends on how correct we model the forming of rogue asteroids and Oort clouds. We can't see or radar them now and they can be more numerous for all we know. Or can we see them after all, not in their star's light, but in the stellar wind of a Nova or Supernova? he...

Exactly. The total mass of the Oort cloud is probably on the order of a few Earths, which is distributed over a massive volume. We could probably sail a probe around in the Oort cloud for thousands of years and never come close enough to a body to detect it. Two Oort clouds passing through each oth...

From over 2 million years ago. What we "see" is what light shows us and light emitted from stars/planets/life on planets in same galaxy is all same. It takes 2+ millions years for light to reach us from there. So, no one knows what happened later (during those 2+ million years when light ...

More like this https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcRC5aOrphDcGCszC7sdRo3fl6sQDq7cG8AK2cQDcWfdCj_6G-4AYNb9C-G_JeTK951F5Mc&usqp=CAU The disk of the moon when low above the horizon should be red. Like when it's a narrow crescent close to the disk of the sun and the sun is low abo...

More like this https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcRC5aOrphDcGCszC7sdRo3fl6sQDq7cG8AK2cQDcWfdCj_6G-4AYNb9C-G_JeTK951F5Mc&usqp=CAU The disk of the moon when low above the horizon should be red. Like when it's a narrow crescent close to the disk of the sun and the sun is low abo...

Do we know for certain that this was indeed a single high energy particle ? And not a whole 'cohort' of particles - arriving together ?? Indeed, Photographing such an event is going to present some challenges This should snapshot individual high energy particles creating a shower in the atmosphere

IF we had a telescope that was powerful enough to see all the way into the Andromeda galaxy, and powerful enough to zoom into a planet that harbored some type of life, would we be seeing images from 2 million years ago or current? From over 2 million years ago. What we "see" is what light...

Wikipedia says our own Oort cloud extends to "distances ranging from 2,000 to 200,000 AU (0.03 to 3.2 light-years)". If another star with a similar Oort cloud passes with, say, 1 ly, the two Oort clouds would pass through each other. So, you're saying that although the gravity of the pass...

Here is a simulation of a major merger resulting in the formation of a large elliptical galaxy. Stars are shown in the left, gas temperature at the right. https://www.illustris-project.org/movies/illustris_movie_elliptical_formation_1pMpc.mp4 Certainly from the perspective of an individual star and...

There is no evidence of "exploded planets" in the Solar System (and no physics to explain such a thing). Asteroids are remnants of material that failed (probably due to gravitational resonance zones created by the gas giants) to coalesce into planets. The total mass of all the asteroids i...

to judge the colour, we can take this pic https://upload.wikimedia.org/wikipedia/commons/5/5c/PIA25726-Jupiter%2BMoonIo-Juno-20230731.jpg and try saturation slider like this Io Saturation+30.jpg there seem to be some pinkish regions and some greenish regions and that can be thought as a struggle of ...

…I used to be taken driving and notice the speckled shadows moving across the carriage, before it occurred to me that they were caused by the leaves overhead. (As soon as I discovered this, the scientific interest killed the impression, and I began speculating as to why the patches of light were alwa...

Sa Ji Tario wrote: ↑Sun Sep 17, 2023 3:05 pm On one side of the lunar limb are the DÁlambert Mountains that look like saw teeth and through whose ravines and valleys sunlight filters to form the Baily Beads.

please which side is the one side?

is it me or the core is quite spherical?
...

do I get it right: this is a dust cloud dimly backlighted by many distant stars, as can be seen at the edges of this APOD frame (and showing dark gray with a brown tint) brightly backlighted by a single star closely behind the dust cloud (in pale cyan to blue to deep violet as the angle of scatterin...

are colours real?
how long is the exposure?
is the ring a true ring in 3d space or just a light echo looking like a ring from the point of view?

Beautiful image! But it looks like the central region of this galaxy is pretty empty of stars - is this really the case? It's an illusion. The central region is nothing but stars! Thanks, Chris. When I look at this flat image, a 2-dimensional elliptical region, or oval, appears to be the main illum...