Starship Asterisk*

a Wolf-Rayet nebula is primarily shaped by the tremendous heat and wind of its own central star Ann I have trouble getting my head wrapped round the way that things work on these scales. If the nebula has something like a 40 light year radius, does that mean that the glow from the nebula has actual...

Is it just me, or is the main APOD link (https://apod.nasa.gov/apod/astropix.html) not working today? It's not just you. Todays APOD is completely blank - really is "open space" :ssmile: Well, it's not so blank now! :D OK. Slow internet (rural Devon) or software update - who knows? But it...

Rauf wrote: ↑Tue May 28, 2024 7:18 am Is it just me, or is the main APOD link (https://apod.nasa.gov/apod/astropix.html) not working today?

It's not just you. Todays APOD is completely blank - really is "open space"

Blue star light does not make purple reflection nebulas! 🤬 Ann The info on the ESA site says The blue, green, red channels capture the Universe seen by Euclid around the wavelength 0.7, 1.1, and 1.7 micron respectively. This gives Euclid a distinctive colour palette: hot stars have a white-blue hue...

So is that little "stem" between 7:00 and 8:00 on the image a jet of some sort? That's the only explanation I can think of. Ann I'm not so sure - on the APOD full sized image, it looks to me as though that "stem" is actually a continuation of one of the limbs of glowing bubbles ...

Some globular clusters have central black holes. I think there are at least two differences. A globular cluster has a different radial density gradient than a galaxy. And a globular cluster has a very different HR diagram than a galaxy, indicating a different formation process. https://upload.wikim...

The typical cruising height of a jet is about 12km and the diameter of the earth is 12,000km so even if the sun is setting on the horizon a shadow would only be cast effectively horizontally (maybe upward at 1 or 2 degrees). But great picture!

why did the swirling clouds freeze in place-was this faked? please answer The clouds on Jupiter are not static. They are moving at speeds of hundreds of miles per hour. But Jupiter is so big (diameter 88,695 miles or 142,800 km) that the clouds don't appear to move significantly during this fly-by ...

Couldn't understand one basic aspect. Why the eclipse is seen starting from west coast in US to east coast in US.. Apparent motion of moon from east to waste should be faster than Sun's apparent motion from east to west.. So I was imagining it'd start from east coast and move towards west coast. An...

Does this mean that the release of gas from the parent body of Pons-Brooks is "episodic"? Like a series of little explosions? Ann It probably depends on the exact chemical composition, the physical structure of the material and how long each surface is in the full glare of the sun as the ...

they are both affected by the hostile environment of the galaxy cluster, so they are transiting away from their spiral shape and gradually shutting down their star formation. Ann Why is the galaxy cluster such a hostile environment for star formation? I would have thought that all the chaotic movem...

Also take a look at an amazing picture of the 300,000 light-year-long tidal tail of NGC 3628! :shock: https://asterisk.apod.com/download/file.php?id=49354&mode=view Tidal tail of NGC 3628. Credit: Mark Hanson. Thanks for highlighting this Ann. It took me a while to realise that the tidal tail o...

Sorry, you have two wrong explanations here. It was NOT the SpaceX Falcon9 rocket from Cape Canaveral. It couldn't be , since that one launched AFTER this spiral event already had occured , and that one did not fly on an orbit far north enough to reach the high arctic skies.... The fact is , it was...

I have only experienced a total solar eclipse under a cloudy sky on a hill top in Dartmoor but it something that I will never forget. If you get the chance this year, than take it. Was it the solar eclipse of August 11, 1999? Yes! That was it. I had cycled for 2 days from Poole in Dorset to get ove...

I have only experienced a total solar eclipse under a cloudy sky on a hill top in Dartmoor but it something that I will never forget. If you get the chance this year, than take it.

some sources say that silver is created in the earth's mantle from sulphur by the intense heat and pressure. That's incorrect. Transmutation of elements requires conditions like those in the core of a star, which are far more severe than those inside any planet. Quoting the Wikipedia article https:...

I was going to add the other astronomical reference for this APOD - that the sliver in this coin was created in supernova explosions billions of years ago, but some sources say that silver is created in the earth's mantle from sulphur by the intense heat and pressure. Can anyone shed light on which ...

That's a spectacular collection of peculiar galaxies @Ann. Or should that be a peculiar collection of spectacular galaxies? Don't forget the spectacular collection of spectacular galaxies, and the peculiar collection of peculiar galaxies. Honestly, I'd like to see both of those collections as well!...

I wonder why the tail of the comet is streaming away from the sun, "buffeted by the solar wind" as in the description, but there seems to be a separate halo around the head of the comet which is more or less smoothly distributed and unaffected by the solar wind?

By the way can anyone spot tiny background galaxies in the APOD? I’m curious to see how those would compare between Hubble and Webb. Looks like there may be one here, right on the left edge of the Webb image APOD1.jpg It's quite visible and blue-ish in the Webb view, but disappears in Hubble.

Items seem to be haphazardly lying around the landing site. Is their placement intentional? The ASLEP monitoring station is only visible as a small speck in the top left near the horizon. On the expanded view you can see it in more detail. All that junk in the foreground is various bits of equipmen...

Good angle, good view, good perspective. Not so usual. I also like that we are able to see some portion of moon that we never get to see from earth but I wish we could see it better (I'm thinking the cameras on Artemis I don't have good resolution), i've never seen so much large portion of the moon...

Looks upside down. How can rockets fall and then shoot back up into the sky? It makes more sense if the camera is pointing more or less overhead tilted, with the launch site to the top left of the frame. The white fluffy trails are where there is side thrust to control booster orientation as it tur...

I'm saying that every (extended) object that is bright enough to see visually through a telescope eyepiece is bright enough to see with the naked eye. All a telescope can do is make it bigger, not brighter. Bigger can make it more visible because more of the retina is involved... but that is exactl...

I'm saying that every (extended) object that is bright enough to see visually through a telescope eyepiece is bright enough to see with the naked eye. All a telescope can do is make it bigger, not brighter. Bigger can make it more visible because more of the retina is involved... but that is exactl...