Starship Asterisk*

Here's an image from the 2024 eclipse, downtown Cleveland. Courtesy of David Petkiewicz (Cleveland.com).
We got very lucky with the weather, just had some thin high clouds.

johnnydeep wrote: ↑Mon Feb 05, 2024 7:42 pm What I really need is an overlay showing where this close-up is in the whole Carina Nebula, and where Eta Carina is!

Based on Wikipedia (first attachment), I think it's as indicated by the arrow in the second attachment.

Are there any estimates of the mass or average density of the California Nebula, and the average density of its surrounding medium? The mass is probably that of several tens of Suns. The density is that of a very hard vacuum. I know the density of interstellar space can vary greatly, but using an &...

Are there any estimates of the mass or average density of the California Nebula, and the average density of its surrounding medium?

Very good!

Here's a version with different background music, the conclusion to Beethoven's Moonlight Sonata:

It is really very interesting that NGC 731 is seen right in front of the galaxy group known as the Deer Lick Group, which is at least 8 times farther away from us than NGC 7331 (some 300-350 million light-years away versus some 40 million light-years away for NGC 7331). I find it interesting that t...

Your mama warned you about those crossed eyes. Keep doing that and they'll be stuck that way forever! :lol2: Crossing your eyes on this image gives an effect, but it is inverted. You get the correct effect if you relax your eyes so that you are focusing on a point beyond your screen (imagine lookin...

johnnydeep wrote: ↑Fri Aug 25, 2023 8:22 pm
Sort of. But that also gives me headache.

It helps if you adjust your image size so that adjacent Saturns appear about 5-6 cm apart on your screen.

You get a neat 3-D effect if you relax your eyes and focus on a more distant spot, like what you do for stereoscopic image pairs. Click below to give it a try. It helps if you adjust your image size so that adjacent Saturns appear about 5-6 cm apart on your screen. [attachment=0]SeasonSaturnapodacas...

What portion is expanding at the rate of 1000 km/s? Presumably the expansion rate falls off as radius squared from the source? So whatever feature is expanding at 1000 km/s it must have moved about 1/20th of a light-year in 14 years.

Wikipedia says it's 1.5 km high - https://en.wikipedia.org/wiki/Mons_La_Hire I don't know. What can we deduce from a close-up of the Google Moon map showing a shadow an a 10 mi scale: Guess we can conclude that a 1-mile-high mountain casting a shadow 100 miles long would need the sun to be only 0.6...

Wikipedia says it's 1.5 km high - https://en.wikipedia.org/wiki/Mons_La_Hire So your height calculation seems to be off. I'll let others figure out why. I know my height can't be correct, that's what I was asking. To put it another way, why does the shadow of the 1.5 km mountain appears to be 80 km...

There is a feature on the upper left near the terminator that casts a shadow of around 40 miles (if my estimate is correct). Based on its distance from the terminator, the sun is about 10 degrees above the horizon, meaning the feature's height is about (40 miles) x tan (10 deg) = 7 miles. What am I ...

Very nice rendering. Do we have any sense of how the sun and background starts would actually appear to a human at that location? I think our pupils would shut down because of the sun's brightness (the apparent magnitude of the sun at that distance is around -18). However, it would be easy to block...

Very nice rendering. Do we have any sense of how the sun and background starts would actually appear to a human at that location? I think our pupils would shut down because of the sun's brightness (the apparent magnitude of the sun at that distance is around -18). However, it would be easy to block ...

johnnydeep wrote: ↑Thu Sep 15, 2022 8:06 pm
Interesting questions! The first is answered here (though not sure how accurate it is) - https://astronomy.stackexchange.com/que ... tem-planet:

Thanks!!

We know what Earth's north star is. What are the approximate north stars of each planet? And what is the sun's north star?

Do all moons have the same tilt as their planet?

JohnD wrote: ↑Tue Jun 14, 2022 12:54 pm Satellites? In a regular grid pattern?

Yes, what is reason for the "graph-paper" effect?

I had the same question. I could imagine some slight misalignment, but they're not close at all. No, the equinox points do not coincide. Earth's orbital eccentricity creates the asymmetric figure 8 as pointed up earlier. For a perfectly circular orbit (eccentricity = 0), the equinox points would co...

rj rl wrote: ↑Tue Jun 21, 2022 7:09 am I'm a bit confused as to why the two equinox lines don't coincide. Shouldn't they?

I had the same question. I could imagine some slight misalignment, but they're not close at all.

Condolences and prayers.

Very nice. How about a "Zenith Moon" with images assembled when the sun is at Lunar noon for each Lunar latitude? Although probably not as interesting since the shadows only appear near the limb in full moon images.

Here's a version with a bit more lively music: the conclusion to Beethoven's Moonlight Sonata. Enjoy!

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"What does the solar wind sound like?" The video below gives the true answer.

Translating particle impact and variable-field data of the solar wind into "sound" is about as meaningful as translating them into Japanese.

Neat comparison! The diameter of the sun as measured from the image only increases by 1.4% from aphelion to perihelion (attached). The measured area increases by 2.8%, which is also the measured increase in "apparent diameter." It is now apparent to me that "apparent diameter" is...