Starship Asterisk*

The " documented by NASA" link to the SDO movie that this clip was apparently processed from shows this (after rotating and flipping to match the APOD): traingular prominence on sun from SDO.jpg So, ignoring the intense heat that close to the Sun, if the Earth were embedded in this promin...

" . . .and so the image was taken before sunrise." If you didn't know the phase was waning gibbous, how could one differentiate from a sunset picture? The location is in the northern hemisphere. The angle of the ecliptic (inferred from the tilt of the crescent) means we must be looking ea...

If you watch scifi shows you’ll notice that to create conflict space ships are subjected to a whole lot of dangerous storms in space analogous to hurricanes and rogue waves to terrestrial ships. “Ion storms”, a “nebula” that wreaks havoc, etc. Have astronomers found anything like that? Assuming a d...

If you watch scifi shows you’ll notice that to create conflict space ships are subjected to a whole lot of dangerous storms in space analogous to hurricanes and rogue waves to terrestrial ships. “Ion storms”, a “nebula” that wreaks havoc, etc. Have astronomers found anything like that? Assuming a d...

In this picture I see little to no asymmetry in the craters that I would expect if the impactor hit at an angle other than 90 degrees to the surface. Now that I think of it, this seems to be common to most of the pictures I have seen of other cratered surfaces. Am I missing something? Or is it the ...

In this picture I see little to no asymmetry in the craters that I would expect if the impactor hit at an angle other than 90 degrees to the surface. Now that I think of it, this seems to be common to most of the pictures I have seen of other cratered surfaces. Am I missing something? Or is it the ...

Quasar, IIRC, stands for quasi-stellar object, something very bright but whose light was anomalously red shifted. They were thought to be at the luminous limits of distance we could see at the time. Now we have a star which is a microquasar? So is M87 then a miniquasar in its core? The term seems t...

Has anyone put together a time lapse of the tiger stripes to see how much they’re changing over the decades we’ve been observing them? The angles and resolutions would vary greatly, but I’m betting some software could blend it together. We only have a few years of high resolution imagery available,...

Christian G. wrote: ↑Fri Aug 23, 2024 2:41 pm Remnants, always remnants… When do we get to see an actual supernova?

Not sure what you mean. We see supernovas all the time. Do you mean nearby? The last one we saw in our own galaxy was in 1604. We're due.
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I'm having trouble understanding cosmic rays. It is defined as a photon. A photon is defined as a particle with no mass. It travels at c. We know that E = mass x (velocity)squared. So how does the photon gain enormous energy, represented as a very high frequency, if it can not have mass, or go fast...

I have always known that a "blue moon" is the term for the 2nd FULL moon of a given month. Is there a term for for the 2nd NEW moon of a given month? The people at Griffith Park Observatory, Los Angeles, couldn't answer my question. Not that I've ever heard. It is worth noting that the te...

That's not correct! The Cocoon nebula is not ionized by young hot stars but by one young hot star, BD+46 3474 , of spectral class B1V! This means that the Cocoon Nebula glows red even though it it not being ionized by even a single O-type star, and not even a single star of spectral class B0, but b...

APOD Robot wrote: Like other star forming regions, it stands out in red, glowing, hydrogen gas excited by young, hot star s , and dust-reflected starlight at the edge of an otherwise invisible molecular cloud. That's not correct! The Cocoon nebula is not ionized by young hot stars but by one young ...

A quiescent prominence typically lasts about a month and may erupt in a Coronal Mass Ejection (CME) Why the adjective "quiescent"? I assume not all prominences result in a CME, right? Do non-"quiescent" prominences end in CMEs more or less often than "quiescent" ones? ...

Thank you, Ann for a very good presentation and an interesting website. However it, like all other depiction of the local region of our galaxy, does not translate the information into a depiction of the sky as you see it when you walk outside on a dark moonless night. Translating those 3-4000 visib...

Like most of us, I was perplexed by the blue wings of the star halfway up the picture, to the right of the Milky Way. After some deliberation, my theory is that this photo was taken with a very wide angle lens. Such lenses tend to have quite a large lens at the front. Their absolute aperture is ver...

Lovely photograph. I have seen green aurora from Iceland, but sadly never red. And a beautiful Perseid meteor streak. I am somewhat annoyed, however, by photographs, often beautiful in the selves which people genuinely believe show meteor tracks, but which, to me, look like satellite trails. The ev...

I wish every APOD would link to the actual source of the image instead of leaving us to ferret it out, along with any pertinent capture details. Here's an interview with this APOD's author on Canadian TV, though even this doesn't give the details of the shot: AUGUST 13, 2024 We check in with local ...

Lovely photograph. I have seen green aurora from Iceland, but sadly never red. And a beautiful Perseid meteor streak. I am somewhat annoyed, however, by photographs, often beautiful in the selves which people genuinely believe show meteor tracks, but which, to me, look like satellite trails. The ev...

Nice! If you are not interested in meteors you can look at the aurora, and if you're not interested in the aurora you can look at the meteors. If you like both, this picture sure has a lot to offer! :D 🥳 I like both! We've had a heck of a monsoon season this summer in Colorado, so rain every aftern...

The APOD is nice, but I think it show us rather too much background and a too small-looking gigantic jet! Although the gigantic jet itself does look fantastic, like a neon-colored mushroom growing out of the cloud cover of the Earth. To me that makes the gigantic jet look even more so, what with th...

The APOD is nice, but I think it show us rather too much background and a too small-looking gigantic jet! Although the gigantic jet itself does look fantastic, like a neon-colored mushroom growing out of the cloud cover of the Earth. To me that makes the gigantic jet look even more so, what with th...

Concerning the fact that the animated orbit INDEED is retrograde: Thanks, I got the point. It is, indeed. Very nice. In order to avoid my misunderstanding with other people, it might be considered to change the start-up viewing perspective of the animation. If you make the start-up view perpendicul...

The second law of thermodynamics says that the entropy of a system is always increasing, and so eventually everything will be in a state of max disorder and "evenly mixed", but looking scenes like the Triffid Nebula (estimated age 300,000 years) it's difficult to imagine that the universe...

As previous posts would have it, those meteors are coming in at 60 miles per second. Care to speculate why some streaks show TWO bright finish burnout flares? 60 km/s. Meteors can't be as fast as 60 miles per second. Meteoroids are very non-uniform, especially when they are cometary dust, which is ...