Starship Asterisk*

Chris, OK, I imagined a simple explanation, and was wrong, but I can do complexity! You will be as short of time as any busy academic - please refer me to some source that will explain the mechanism? Neufer, Thank you! So the blue is due to Oxygen, not Helium? But why is that fluorescing near the st...

The intense spectrum of colours across the Ring Nebula represent the different elements being ionised and then fluorescing at a distinct frequnency and colour. So the spectrum represents a gradient of elements in the nebula that depends on their distance from the star. How does this gradient form? I...

Good point, neufer! Nicely made! And lava tubes are a feature of both Earthly and Lunar geology. So, perhaps a coating of ice over a flowing river of water? BUT! Look at the shape of the Virgil Fossa as it approaches Elliot (click on my pic above for an enlarged version) The Fossae are jagged rifts,...

Thank you, neufer, and Ann for the tutorial on cryovolcanism! But I repeat - there is no possibilty of liquid water on the surface of Pluto, or of amonia in liquid form, or methane either, when the appearance of the Virgil Fossae as it approaches Elliot resembles an eroded water channel. Ice II or I...

Is this for blind astronomers? I have no doubt there are some, and good luck to them! Rather than how far, 'What'? What is the object almost in the centre of the field, that looks like a diagonal bar of light? There is a single bar just above it, and several others elsewhere in diofferent orientatio...

Ann makes a case for the Sputnik Platina having been liquid at some time. Does this ignore the abilty of some 'solid' substances to flow over long periods of time? Such as shown by the U of Queensland's Pitch Drop experiment? 800px-University_of_Queensland_Pitch_drop_experiment-white_bg.jpg And, I n...

Oops? The "discuss" link from the APOD of 7/31/2021 - https://apod.nasa.gov/apod/ap210731.html - links to this old APOD discussion. How does an aerial photo of a rocket launch "link" to a ground based picture of the Great Bear and Comet NEOwise? Apart from the hyperlink that joh...

If you zoom in on the eliptical galaxy left mid. you see something that actual looks like a black hole as it would be in visible light passing in front of it low right. I can't upload pictures otherwise I could show it. It's not. Black holes can't be optically resolved. They're far too small. Not t...

Like the famous picture of Hoag's Object https://apod.nasa.gov/apod/ap100822.html in which another ring galaxy appears in the background, this picture does the same. Ann's Object No.4 (bottom left) appears to be very similar to AM 0644-741!

JOhn

AaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaH! The "Attachments" button!! Thank you, johnny!
Just to check, a quick shot by mobile of the half moon in my sky.

JOhn

And it works! I promise not to abuse!

XgeoX, I'm looking at the 'Full Editor' now. It has an "Insert Image" button which generates pairs of square backets, with 'img' and '/img' in them. But pasting anything into the space in the middle gets nothing. There's something in the FAQ about posting images that are online, not on one...

Several members above have posted images. I see from the FAQ page that image posting is allowed if so enabled for that thread (which clearly has been done) and if that member has the priviledge. May I post images, please?
JOhn

And to prove that great minds think alike, see:
https://epod.usra.edu/blog/2019/07/the- ... moon-.html

See: http://adsabs.harvard.edu/full/1989LPI....20..185C

Both of those are "Rille", a German word for 'groove' that seems to be given a Latin name in the plural, "Rimae", for some reason. They may be straight or more usually 'sinuous'. There are many rimae on the Moon and other bodies of the Solar System, and many explanations for them...

A very good point, Chief Dan! Looking again at the APoD, the dark part is dark, all over. The white part has many black spots, as if from incomplete coverage or later erosion of a white covering. That giant crater near one pole (of the image, possibly not the real pole) has the rim on the side neare...

John Milton knew a thing or two about dark material Into this wild abyss, The womb of Nature and perhaps her grave, Of neither sea, nor shore, nor air, nor fire, But all these in their pregnant causes mixed Confusedly, and which thus must ever fight, Unless the almighty Maker them ordain His dark ma...

Thnak you Art! "Within the bright regions there is no ridge, but there are a series of isolated 10 km peaks along the equator. "
Now I see it! Within the dark area.
John

Indeed, a fascination toy, to roll and bauble with! But I'm missing the "equatorial ridge". If I can see it then the axis that the image spins on passes through it, so it should be called the transpolar ridge, but this may be a product of the passage of Cassini past the moon, rather than i...

https://vecta.io/symbols/198/symbols-geometric/32/black-large-square If you look VERY carefully, you can see a cat in the picture above. The cat is black, it was taken in a coal celler at midnight and the photographer's flash gun failed. Just thought you would like to know the technical details of t...

So January 4th, the next perihelion we will have a SUPERSUN! 'Cos it will be 3% bigger!!!!
Break out the whoowhoo flags, invent new names for these aspects, just like all the flimflam about the Moon that is so boring.

Nice pics!

Thank you, Chris!

What do you mean, EM? That Andromeda should have been bigger in the sky? That would have screwed up the Milky Way, which it will do, one day in the future, as we rush towards it! It's the only galaxy that's naked eye visible, and was known when the Ptolomeic model of the Universe reigned, but as a '...

Set the ccontrols for the heart of the Sun/Galaxy! Fire when she bears, Mr.Mate!

You don't think this minor planet sized comet is of that much interest, Chris? Other missions have been launched (OsirisREX, Hayabusa) to bring back specimens of primordial material. Something from the Oort Cloud is as primordial as they come! A specimen return mission would seem beyond possibility ...