Starship Asterisk*

Thanks geckzilla

[quote="Confused Perspective" post_id=300263 time=1583860082]
I never have understood the perspective of these types of shots. If we are within one of the spiral arms of the galaxy, how can this perspective of an arm be achieved from earth? Either we'd be looking out from within the same arm in the image and it doesn't make sense to me that it would look so sharp and defined, or we are looking at another arm and I would think it too far away to image from an earth based device plus the angle of the arm wouldn't make sense because we should see it edge-on being spiral galaxies more or less occupy a flat plane?
[/quote]

It's impossible to differentiate one arm of the Milky Way from another from looking at am image like this. We are viewing the disk of the MW, have a bit less than a 180° view, and can see the central bulge. Dust that seems to extend far above or below the plane is mostly a trick of perspective because it is relatively close to us.

I never have understood the perspective of these types of shots. If we are within one of the spiral arms of the galaxy, how can this perspective of an arm be achieved from earth? Either we'd be looking out from within the same arm in the image and it doesn't make sense to me that it would look so sharp and defined, or we are looking at another arm and I would think it too far away to image from an earth based device plus the angle of the arm wouldn't make sense because we should see it edge-on being spiral galaxies more or less occupy a flat plane?

[quote="Chris Peterson" post_id=300236 time=1583768110 user_id=117706]
[quote="orin stepanek" post_id=300235 time=1583766781 user_id=100812]
[quote=Ann post_id=300233 time=1583765748 user_id=129702]
Thanks for your explanation, Chris.

Ann
[/quote]

Ditto! At first i thought ot was a fisheye camera until I read the (over 30 exposures) explanation in the writeup!
[/quote]

When you stitch together a bunch of images into a panorama, the stitching software typically offers multiple choices for the mapping used. "Fisheye" is one of those choices, where the resultant image will have the same kind of distortion that most fisheye lenses produce (cleverly known as "fisheye distortion"). There are other choices, as well, most long known to map makers.
[/quote]

Thanks again Chris! 8-)

[quote="orin stepanek" post_id=300235 time=1583766781 user_id=100812]
[quote=Ann post_id=300233 time=1583765748 user_id=129702]
Thanks for your explanation, Chris.

Ann
[/quote]

Ditto! At first i thought ot was a fisheye camera until I read the (over 30 exposures) explanation in the writeup!
[/quote]

When you stitch together a bunch of images into a panorama, the stitching software typically offers multiple choices for the mapping used. "Fisheye" is one of those choices, where the resultant image will have the same kind of distortion that most fisheye lenses produce (cleverly known as "fisheye distortion"). There are other choices, as well, most long known to map makers.

[quote=Ann post_id=300233 time=1583765748 user_id=129702]
Thanks for your explanation, Chris.

Ann
[/quote]

Ditto! At first i thought ot was a fisheye camera until I read the (over 30 exposures) explanation in the writeup!

Thanks for your explanation, Chris.

Ann

[quote=Ann post_id=300227 time=1583733036 user_id=129702]
[float=right][img3="Milky Way and Zodiacal Light over Chile
Image Credit & Copyright: Roman Ponča (ht: Masaryk U.)"]https://apod.nasa.gov/apod/image/2003/ZodiacalMw_Ponca_960.jpg[/img3][/float]Some kind of photographic technique has been used to make all straight lines look curved in this picture. The light pole looks rather drunk, for example.[/quote]

No technique has been used. It's just the consequence of mapping a sphere onto a plane. Something always has to give. (That's why countries lying far to the north or south tend to look way too big on most maps.) You can't make a wide angle image where all the straight lines in the 3D world appear so in a 2D projection (projections which try to achieve this create even more bizarre distortions). We almost always see this in Milky Way images, of course- a straight structure that appears as an arc in images.

[quote=Ann post_id=300227 time=1583733036 user_id=129702]
[...] as if the Milky Way in Vela was firing a pop corn machine gun of stars into the sky until all the pop corns popped all together to create the light show that is the LMC.

Ann
[/quote]

That's a "colourful" way of commenting!
B^)

[float=right][img3="Milky Way and Zodiacal Light over Chile
Image Credit & Copyright: Roman Ponča (ht: Masaryk U.)"]https://apod.nasa.gov/apod/image/2003/ZodiacalMw_Ponca_960.jpg[/img3][/float]Some kind of photographic technique has been used to make all straight lines look curved in this picture. The light pole looks rather drunk, for example. I don't mean it as a criticism.

Anyway, some of the effects on the sky (of this technique?) are interesting. My favorite effect is the apparent stellar stream connecting the Large Magellanic Cloud to the "end" of the Milky Way, as if the Milky Way in Vela was firing a pop corn machine gun of stars into the sky until all the pop corns popped all together to create the light show that is the LMC.

There is a milder but still interesting effect emerging from the other end of the Milky Way. There is what looks like a dividing line in the sky, on whose left side the night sky is bluish and on whose right side it is sort of brown.

And the Zodiacal light? Oh, I like it! :D

Ann

[url=https://apod.nasa.gov/apod/ap200309.html] [img]https://apod.nasa.gov/apod/calendar/S_200309.jpg[/img] [size=150]Milky Way and Zodiacal Light over Chile[/size][/url]

[b] Explanation: [/b] What is the band of light connecting the ground to the Milky Way? [url=https://en.wikipedia.org/wiki/Zodiacal_light]Zodiacal light[/url] -- a stream of dust that orbits the [url=https://solarsystem.nasa.gov/solar-system/sun/overview/]Sun[/url] in the inner [url=https://solarsystem.nasa.gov/solar-system/our-solar-system/in-depth/]Solar System[/url]. It is most easily seen just before sunrise, where it has been called a [url=https://apod.nasa.gov/apod/ap120116.html]false dawn[/url], or just after sunset. The origin of zodiacal dust remains a [url=https://ui.adsabs.harvard.edu/abs/2002Icar..158..360H/abstract]topic of research[/url], but is hypothesized to result from [url=https://apod.nasa.gov/apod/ap130812.html]asteroid[/url] collisions and [url=https://apod.nasa.gov/apod/ap200127.html]comet[/url] [url=https://apod.nasa.gov/apod/ap170409.html]tails[/url]. The featured wide-angle image shows the central band of our [url=http://www.atlasoftheuniverse.com/galaxy.html]Milky Way Galaxy[/url] arching across the top, while the [url=https://en.wikipedia.org/wiki/Large_Magellanic_Cloud]Large Magellanic Cloud[/url] (LMC), a [url=https://en.wikipedia.org/wiki/Satellite_galaxies_of_the_Milky_Way#Map_with_clickable_regions]satellite galaxy to our Milky Way[/url], is visible on the far left. The image is a combination of [url=https://external-preview.redd.it/livb5VRT7pdr0Snw1_gBsUwdvIdUZC9qgye-CIn8xy0.jpg?width=640&crop=smart&auto=webp&s=11e2b2e2db6388775e74b427c42ec8c11646b686]over 30 exposures[/url] taken last July near [url=https://www.youtube.com/watch?v=OXsJAsfEmtU]La Serena[/url] among the mountains of [url=https://en.wikipedia.org/wiki/Chile]Chile[/url]. During the next two months, [url=https://skyandtelescope.org/observing/see-shoot-zodiacal-light02042105/]zodiacal light[/url] can appear quite prominent in northern skies just after sunset.


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