Starship Asterisk*

Wow, nearing 10 years son the surface! Not moving very fast, just about 2.7 km covered per year. It has achieved some great science objectives. ( https://mars.nasa.gov/msl/mission/science/results/ ) Detected all kinds of signs of the presence of water in the past (and the evident scarcity of it toda...

... Normally, the ISS itself is brighter than the sunlit face of the Moon, so if you image it crossing the Moon during the day, you'll see it as a bright object, not a silhouette. (See http://www.cloudbait.com/20200604_iss-moon.php as an example.) Which means you'll also see it against the shadowed...

Certainly easy to spot where we will have our permanently staffed base, and the path to follow to collect ice every day. Less clear is what the inhabitants will do with themselves every day. Gather rocks? I would suggest build space telescopes in that permanently dark region and hunt for new exopla...

First, let me say that I appreciate these answers, from Chris and alter-ego. Also, the further comments that Ann and johnnydeep have added. An easy response to my post would have been something like: "No, you just need to take one or more courses that cover this, then you'd get it. Until then, ...

scotfree wrote: ↑Tue Apr 05, 2022 4:57 am (above)

Thanks for posting that really wonderful note and bio, Stephen.

It helps me know more about the man. It seems that another of Art's most significant accomplishments that I never knew about, was to have raised an impressive group of next-generation Neuendorffers.

The CMB is defined by photons that have been in flight for 13.6 billion years. We see their origin in a shell around us. How would those photons be different if they had been in flight for 20 billion years? How could they have been in flight for greater than the age of the Universe? If the redshift...

Chris Peterson wrote: ↑Mon Apr 04, 2022 4:28 pm The CMB is defined by photons that have been in flight for 13.6 billion years. We see their origin in a shell around us.

How would those photons be different if they had been in flight for 20 billion years?

Oh, this news hurts. I only ever knew Art through this forum. But it was always a delight to see what his next post would be, even when he was simply correcting my mistaken ideas. The beautiful and thoughtful posts of you who are here is comforting. Art chose the tagline "Vacationer at Tralfama...

Of course, scientifically, a star's color is largely unrelated to its appearance. It's a classification based on the shape of its blackbody spectrum. It's temperature. So the Sun is, quite correctly, classified as yellow. The scientific classification of the Sun as "yellow" is about as ab...

If you crop it for 18 months you get a sexy lady! Eric I don't know the definition of keogram. A quick search does not find it in a dictionary or Wikipedia or Wiktionary. I wonder who coined the term, and if it is named after someone, or if "keo" is a reference to something. Some of the l...

Very apropos that it is an hourglass shape! . . . Eric Ahh, you are a person focused on the night. To a daylight-focused person, it looks like a bulge. :-) Okay, honestly, regardless of whether you pick day or night, the long-term pattern for Mid-Latitude day/night lengths is: DayLengthMidLatitudes...

This is a fantastic APOD. Thank you also for all the comments. I have often wondered about the phraseology used to define the limits of our universe. This makes it more reasonable that our "observable" universe is 13.4 billion years old rather than "the" universe is 13.4 billion...

Explanation: How far can you see? Everything you can see, and everything you could possibly see, right now, assuming your eyes could detect all types of radiations around you -- is the observable universe . Not the observable universe, but an observable universe. Every observer in the Universe has ...

Wow, I've never seen one of these before. The "refraction and reflection" linked article says "The circumzenithal arc, or 'smile in the sky' is fairly common but is rarely seen." I wonder if there is any weather data that could help one to know when such a wonder is more likely t...

Can't keep this from you... . . . Lots of info on 47 Tuc and the SMC . . . Ann Thanks, Ann, very interesting stuff. I couldn't find your "2 o'clock" blue straggler until you marked it in your second post. Thanks! I would have guessed that your very bright "4 o'clock blue straggler&qu...

Another lovely image that shows how one can change the lighting and help the eye see different features! I'm reminded of the "Terminator Moon" image used for February 15's APOD, with this one begin very different. Today's image looks a lot like an etched-glass globe to me. Whereas the 2022...

I do think you missed an obvious nebula, down in the right corner of the image. I believe it's called the Playful Kitten Nebula. playful kitten.jpg (not sure this is working, but it appears as a kitten standing up, batting at something) Capture3.PNG Ahh, I think I see that one. Although searching f...

Uhhh, maybe at the upper left, but I don't think I see it either.
A very nice image, nevertheless. Overall, it looks like a striking, bright orange version of the northern lights.

How much time does it take for a prominence this large to come into being? A few seconds, minutes, hours? https://en.wikipedia.org/wiki/Solar_prominence Prominences form over timescales of about a day and may persist in the corona for several weeks or months, looping hundreds of thousands of kilome...

Today's (1/30/22) beautiful shot of the enormous solar prominence from 1999 poses my question: how long is such an individual event visible... how long does it last? https://en.wikipedia.org/wiki/Solar_prominence Prominences form over timescales of about a day and may persist in the corona for seve...

"called the Snow Moon by some northern cultures" No they don't. Even the link says "Some North American tribes named it the Hunger Moon" and lists some other fanciful names without any attribution. Are you an expert in North American Native cultures? The link goes to an article ...

Very nice, it certainly does bring out some of the features. On the other hand, it reduced the visibility of rays. To the point that I'm like "Where's Tycho?" Yeah. Now why exactly is that? At least one crater still does have very prominent rays, so why don't all of them? And another star...

Very nice, it certainly does bring out some of the features. On the other hand, it reduced the visibility of rays. To the point that I'm like "Where's Tycho?"

Did anyone notice the pink ring at the top of the image and if there is a designation for it? Good question! WeBo 1 is a planetary nebula in the Heart Nebula and thus in the constellation of Cassiopeia, named after its discoverers Ronald F. Webbink and Howard E. Bond. The planetary nebula is formed...

Yes, the figure does look a little like Gort, from the 1951 film.