Starship Asterisk*

The image doesn't make a lot of sense; in particular, I'm having a lot of problems with the lights reflected in the water. The reflections are much brighter than the lights themselves, and in one place there are reflections that don't even seem to have sources.
This must have been heavily processed.

the interesting illusion about today's Astronomy Picture of the Day of the Eagle Nebula is that our brains see the blue as a hole in the dark clouds showing sky behind.
But the sky in space is black, not blue. The blue is also a cloud, at about the same distance at the others.

Yeah, I'm having a lot of problems seeing four halos in this image. The text "a (third) rainbow-like arc 46 degrees from the Moon" followed by "furthermore, part of a whole 46-degree circular halo is also visible" seems to count the 46 degree halo twice, is it implying that there...

"The featured high-resolution time-lapse video was captured over five nights earlier this month by a mid-sized telescope on an apartment balcony in Paris, France." Paris has a day night cycle (not to mention Jupiter rising and setting)... How did they get five days of images without being...

I think in this case "mere" is intended as understatement.

I'm puzzled, why is the left limb of the moon outlined as a thin yellow line as it crosses the solar disk?
Is that an artifact of unsharp masking, or something?

So... if you were standing directly underneath the Gateway Arch in St. Louis, you wouldn't describe it as an arch? Exactly the opposite. This APOD image is something that is not actually an arch, but looks like an arch in the picture. What you are describing is something that is an arch, but would ...

Nice explanatory video, but do notice that this is an old video from before the Curiosity landing. The new Perseverance landing animation can be seen here: https://astronomynow.com/2020/12/28/perseverance-landing-another-7-minutes-of-terror-for-nasa/ (and I like some of the things they did on the ne...

Yeah, I'm a little puzzled by the photo being described as "arches".
There are no arches in the picture. What visually looks like arches is simply the image being badly distorted, due to compressing about 300 degrees of panorama onto a flat page.

There's no distinct dividing line between a manipulated image and an unmanipulated image-- pretty much all the images have some processing-- but this one could reasonably be more accurately described as "a photo of Venus and the moon at twilight, onto which was photoshopped an image of the Plei...

The featured image captured this cosmic triangle with a series of exposures taken from the same camera over 70 minutes Wait, what? Objects in the sky move at fifteen degrees an hour. The frame of the picture is maybe five degrees or so. If the picture took seventy minutes to take, nothing in the im...

Just for context, it would have been nice if it included the Goldilocks zone around F stars, about 3% of the stellar population, and 2-4 billion year lifetimes. The wild card for F stars will be the UV. I will expect that the UV will be attenuated by atmospheric ozone in a planet of a F star, but th...

I do have to say I found this one confusing and hard to follow. The sun seems to be doing the usual analemma thing.... then abruptly takes a right-angle turn in the sky. This is not a composite of the analemma; it is the analemma composite overlaid with a bunch of mostly-unlabelled sunset positions,...

They say that the Great Red Spot is shrinking, but in this picture is looks very large Yes, that is the "perspective distortion" briefly mentioned in the caption. It's a fisheye lens effect, basically. We're looking at a nearly flat surface from close up. The apparent spherical shape of t...

They say that the Great Red Spot is shrinking, but in this picture is looks very large Yes, that is the "perspective distortion" briefly mentioned in the caption. It's a fisheye lens effect, basically. We're looking at a nearly flat surface from close up. The apparent spherical shape of t...

True. But over the five billion years that the sun has been around, even a very very slight self interaction would equilibrate the concentration.

... There is no evidence that dark matter is concentrated in the Solar System, or in the Sun or planets. (No evidence doesn't mean it isn't, just that for now, there's no reason to believe it is present, and we have no observations that would be better explained by positing a dark matter involvemen...

I'm puzzled. Why are the solar prominences bright, instead of dark, if it's inverted?
And why is the sun surrounded by a bright halo in the image on the right, but not on the left?

Try this and recall Opportunity's exploits. Better seen on a mobile phone, because then as you turn and pan, the view moves with you, as if you have a porthole out onto the surface of Mars: https://www.360cities.net/image/mars-opportunity-rover?fbclid=IwAR0qA58m1umDDt6U4IaQozQK-UfTOEEHum6dUwMtgUGyH...

The date in the corner fo the image is a little inconsistent. Sol 5074 was the beginning of May, not June. (June was the last time we heard from Opportunity).

Suppose the solar minimum does go deeper. What effect will that have on Earth? The correct answer is that climatologists have been looking for a correlation between solar activity and climate for the last 400 years, while many such correlations have been proposed, so far none of them have turned ou...

Amazing picture. I'm struck by the fact that the disk of the sun is brighter on the limb-- this gives a great visualization of the sphericity of the sun, but I would have expected limb darkening. Why is the limb bright?
(http://spiff.rit.edu/classes/phys440/le ... /limb.html)

The moon would have been my first thought, but since we're looking pretty much north, it was hard for me to think the moon could be behind the mountain. Could be-- I suppose I could fire up a planetarium program and check.

This is a nice image-- very evocative; great use of color.
I'm curious, though-- what's the light source for the sky?

"These neutron stars were billions of years old and probably quite cold." I will point out that they could not possibly be more than 13.8 billion years old. The surface area of neutron stars is so small that they just can't radiate energy well. The word "quite cold" in your stat...