Starship Asterisk*

I really appreciate the nice pink / magenta Hydrogen Alpha emission :) H-alpha isn't pink! It's deep ruby red. I think what you mean is that you appreciate that you're seeing some combination of H-alpha, H-beta, and continuum radiation that is resulting in a pink color. You are absolutely right Chr...

I really appreciate the nice pink / magenta Hydrogen Alpha emission

The argument is that landing on the launch mount is better for rapid re-use, as opposed to just normal slow re-use. If landing in the chopsticks is approximately the same order of magnitude difficulty as landing with legs, then you gain both the mass advantage from not carrying the legs, but also on...

There is no certification or evaluation for the title of "expert" astrophotographer, only experience, so I will slightly disagree with Chris here and agree with the commentator who provided order-of-magnitude reasoning. I could claim to be an expert myself, I have decades of experience wit...

Hey Zendae, thank you for linking that paper, that is really interesting to me, I'm going to be absorbed in that and related literature for a little while, thank you very much. And haha Johnny Deep I agree, it does seem incomprehensible to me, maybe it is FRS or some other such abbreviation, but it ...

Thank you very much Chris for more info! You asked "Is there some such suggestion being made by anybody"? And perhaps I misunderstand your tone, but the answer is yes, hello, it's me, I'm not alone, there are literally dozens of us, maybe, making the suggestion for photography presented to...

Hahaha, Ann, that's great, thank you, I'm saving that hawk image. Hawks probably love Europa, who's to say? But may I please continue discussion about the proportion of H-beta. I certainly willing to be wrong about anything, including the reason for the solar prominences appearing pink, I agree Chri...

Haha, wonderful examples of not-comets. I would say the top unappreciated not-a-comet is when you have a smudge on your lens. Just a little more pedantic color discussion. I have seen hydrogen emission with my own eyes from the sun during a total eclipse, and it appears neon pink, not deep red. Hydr...

I'd like to share a piece of trivia about a tiny background detail in this photo, in the tradition of APOD commenting, haha. Do you see those wires in the middle of the frame, they look maybe like power lines? They are actually part of the Lightning Protection System which surrounds the rocket. I al...

This type of triangular structure, drawn several times next to a circle, is exactly how I would draw the sun as a child, along with fellow untold millions of children drawing the sun like this! We were right all along haha!

Another fun game of "what's that star!" The tiny, slowly moving star is definitely a satellite, the time of night here is closer to sunrise than sunset, and they are looking east, into the part of space already lit up with sunlight, a great time to see satellites and tumbling rocket bodies...

So, can I assume that the trail of the Electron rocket was made by a separate set of exposures? It can't just be there over the 2.5 hours of the 50 exposures to make the star trails, can it? Yes, it probably is. I mean, it could be done either way. But practically, with wide launch windows, the exa...

I always appreciate your posts Ann, and I also love playing "what's that star"! We can figure it out with some free planetarium software like Stellarium and the launch location and time. Looking at Rocketlab's press release, we also get an idea why maybe this photographer was taking a two ...

Western USA will get a similar view just before sunrise on September 17th, and Saturn's opposition is September 8th, so even as dim as the light from Saturn can appear next to the moon, this will be about as bright as it gets. All the Hawaii observatories should have a nice view, I hope somebody doe...

Take the comparison of 3 million light years to 3 ten-thousandths of a light second - what is that for? (The latter number works out to 5.6 miles and so is probably wrong, too many decImal places, as that meteor track is most likely starting at least 50 miles up) By my calculations 0.0003 light sec...

What a spectacular shot! I love thinking about how the light from the galaxy is relatively constant, from an amateur instrument, M33 is always going to look the same, every night, for the rest of our lives and a long time into the future. But that meteor barely lasted a second, and you'll never see ...

If you love clouds and you love astronomy then no matter what condition the sky, you'll enjoy a look up after sunset! But I also love nitpicking... today's APOD says that iridescent clouds are "relatively rare" but they are actually very common. If there are no clouds, you can't see irides...

It would have helped to label this image, as I can't tell from the text exactly what I'm looking at—confusing at best. I really like when APOD does "mouse-over" annotated images, that's a good compromise between clarity and the beautiful view without text labels. Haha, and I know you mean...

Beautiful! So we only get to see Titan's shadow on Saturn about once every 15 years, right? I was looking up in Stellarium and it looks like there will be several visible passes around this time next year.

The image is striking (pun intended). The number of Jets is a good question. It appears that there are 5 with 2 converging and one (on the right) diverging. But, I am wondering what is the bright object in the middle of the frame? to answer that we need to recognize the star field. Is there a star ...

Maybe I'm wrong, but that "jet" of material looks exactly like a low Reynolds number smoke simulation. I happen to have more than a decade of painful experience with numerical simulations of turbulence. The rule of thumb for analysis via Reynolds number is that you measure the characterist...

"a multitude of planet-dwarfing active regions"

Since dwarf planets are dwarfed by planets, by the transitive property, these planet-dwarfing regions must be dwarf-planet-dwarfing!

Another one: If it's blinking but appears too high to be an aircraft, or even more mystifying, if the blinking is irregular! - it's a tumbling satellite. Yep, and slow but steady brightness changes would likely be the giant tumbling rocket body stage left in orbit after releasing a satellite, I saw...

I was thinking what Ann has labeled object 8 is a dusty galaxy, and I thought I saw several dusty looking galaxies while zoomed into this image... but this is NIRCam, and when it takes pictures around the local milky way, it makes dust look transparent. So is this light really so distant that it use...

In a nearby alternate universe, this image shows the Olympic torch being lit at the top of the Eiffel Tower by orbital laser! Haha, I wonder what they will actually do, the 2024 summer games in Paris are just a month or two away.