APOD: Comet Clark is near the Edge (2017 May 27)

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APOD: Comet Clark is near the Edge (2017 May 27)

Post by APOD Robot » Sat May 27, 2017 4:07 am

Image Comet Clark is near the Edge

Explanation: Sweeping through this stunning field of view, Comet 71P/Clark really is in the foreground of these cosmic clouds. The 2 panel telescopic mosaic is color enhanced and is about 5 degrees (10 full moons) across. It captures the faint comet's position on the night of May 23/24 over 5 light-minutes from Earth, very near the line-of-sight to bright star Antares and the Rho Ophiuchi cloud complex. In the frame Antares, also known as Alpha Scorpii, is at bottom center surrounded by a dusty cosmic cloud reflecting the cool giant star's yellowish light. Globular star cluster M4 shines just right of Antares, but M4 lies some 7,000 light-years away compared to Antares' 500 light-year distance. Slightly closer than Antares, Rho Ophiuchi's bluish starlight is reflected by the dust in molecular clouds toward the top. You can spot the small coma and short tail of the comet as a faint smudge near the center of the left edge of the frame. Just look for the comet's striking greenish color, produced as diatomic carbon molecules fluoresce in sunlight.

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Ann
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Re: APOD: Comet Clark is near the Edge (2017 May 27)

Post by Ann » Sat May 27, 2017 7:28 am

Image
Giant elliptical galaxy M87, and (clockwise) NGC 4476, NGC 4478 and NGC NGC 4486A.
Photo: Robert Gendler.


















We live in the days of cosmic latte. Take a sip. It tastes pretty good, but it is pretty beige.
NGC 1313. Photo: Warren Keller.
That boring color is the elliptical galaxies' fault. They have used up much of their gas and heated and stirred up the rest of it so that it's no good for star formation. All the stars they sport are Arcturuses, Polluxes, a few Sunlike stars like Alpha and Beta Centauri and terrible numbers of little red Proxima Centauries.

There are, of course, still starforming galaxies in the nearby universe, like NGC 1313 at left. They sport flamboyantly bright blue stars and rosy-pink emission nebulas. And every time you see some pictures of some striking pink-and-blue stuff in the Milky Way, you are looking at star formation.
Ghost of Jupiter, planetary nebula NGC 3242.
Source: leviathanastronomy.com.





But the green stuff is scarce in the universe. It is mostly seen in planetary nebulas and - yes, in comets, of course!









So in today's APOD we see Comet Clark at far left, heroically flying past the backdrop of yellow, red and blue splendour of the Milky Way. I can't help it, ever since my avid Superman-reading days as a kid I associate the name Clark with Superman. I can't help picturing Comet Clark as a tiny little man in a brilliant green cape, a fearless little superhero of the cosmos adding a tiny, tiny glint of green to the local fireworks of red, yellow and blue and the vast, vast cosmic latte.

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Re: APOD: Comet Clark is near the Edge (2017 May 27)

Post by neufer » Sat May 27, 2017 12:57 pm

Ann wrote:

So in today's APOD we see Comet Clark at far left, heroically flying past the backdrop of yellow, red and blue splendour of the Milky Way. I can't help it, ever since my avid Superman-reading days as a kid I associate the name Clark with Superman. I can't help picturing Comet Clark as a tiny little man in a brilliant green cape, a fearless little superhero of the cosmos adding a tiny, tiny glint of green to the local fireworks of red, yellow and blue and the vast, vast cosmic latte.
One might just expect "a girl!" to get this all wrong.

The kid in the photo is clearly dressed as the Green Lantern.


And 71P/Clark is not green due to
fluorescent diatomic carbon molecules
but simply because it is a remnant
of the green Planet Krypton :!:
Art Neuendorffer

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Re: APOD: Comet Clark is near the Edge (2017 May 27)

Post by Chris Peterson » Sat May 27, 2017 1:49 pm

Ann wrote:
Image
Giant elliptical galaxy M87, and (clockwise) NGC 4476, NGC 4478 and NGC NGC 4486A.
Photo: Robert Gendler.


















We live in the days of cosmic latte. Take a sip. It tastes pretty good, but it is pretty beige.
gray1.jpg
gray2.jpg


















Stand back far enough, and averages tend to be pretty... average.
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Chris

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Re: APOD: Comet Clark is near the Edge (2017 May 27)

Post by Ann » Sat May 27, 2017 3:58 pm

neufer wrote:
Ann wrote:

So in today's APOD we see Comet Clark at far left, heroically flying past the backdrop of yellow, red and blue splendour of the Milky Way. I can't help it, ever since my avid Superman-reading days as a kid I associate the name Clark with Superman. I can't help picturing Comet Clark as a tiny little man in a brilliant green cape, a fearless little superhero of the cosmos adding a tiny, tiny glint of green to the local fireworks of red, yellow and blue and the vast, vast cosmic latte.
One might just expect "a girl!" to get this all wrong.

The kid in the photo is clearly dressed as the Green Lantern.
Martian Manhunter Minimalism by AtomicKittenStudios.
The real Comet Clark?
I knew you'd say that, but you're wrong!

Ever seen Green Lantern wearing a cape? I haven't! And what is the tail of a comet, if not the superhero's cape?

Of course, the tail of a comet tends to be blue(ish), while the coma, corresponding to the hero's head, is green. So maybe the little green superhero in today's APOD is really the Martian Manhunter?

















And 71P/Clark is not green due to
fluorescent diatomic carbon molecules
but simply because it is a remnant
of the green Planet Krypton :!:
Haha! Okay, I'll accept that! :arrow: :lol2:

Ann
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Re: APOD: Comet Clark is near the Edge (2017 May 27)

Post by De58te » Sat May 27, 2017 4:13 pm

Superman wore a red cape, although he also wore blue and yellow. But the big point is, have you ever seen Superman wear a green or any color mask?

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Re: APOD: Comet Clark is near the Edge (2017 May 27)

Post by neufer » Sat May 27, 2017 4:44 pm

Ann wrote:
Ever seen Green Lantern wearing a cape? I haven't! And what is the tail of a comet, if not the superhero's cape?
https://en.wikipedia.org/wiki/Alan_Scott wrote: <<The original Green Lantern was created by an American artist named Martin Nodell. Nodell mentions Richard Wagner's opera cycle The Ring of the Nibelung and the sight of a trainman's green railway lantern as his inspiration. After seeing this opera, Nodell sought to create a superhero who wielded a variety of magical powers from a magic ring, which he regularly recharged from a green lantern. Nodell wanted a colorful and interesting costume for his character, deriving from elements of Greek mythology.

Green Lantern is famous for the oath he recites when he charges his ring:
  • ...and I shall shed my light over dark evil.
    For the dark things cannot stand the light,
    The light of the Green Lantern!
Nodell chose the name "Alan Scott" by flipping through New York telephone books until he got two names he liked. The character of Alan Scott made his debut in All-American Comics #16 (July 1940), fighting crime under the masked identity of "Green Lantern". His villains tended to be ordinary humans, but he did have a few paranormal ones, such as the immortal Vandal Savage and the zombie Solomon Grundy.

In 1941, Alan Scott was paired with a sidekick named Doiby Dickles, a rotund Brooklyn taxi driver, who would appear on a regular basis until 1949. In 1948, Alan also got a canine sidekick named Streak. The dog proved so popular that he starred in his own solo side-stories.>>
De58te wrote:
Superman wore a red cape, although he also wore blue and yellow.
But the big point is, have you ever seen Superman wear a green or any color mask?
Art Neuendorffer

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Re: APOD: Comet Clark is near the Edge (2017 May 27)

Post by Amy Farrah Fowler » Sat May 27, 2017 5:35 pm

This looks like the television series "Big Bang Theory"
:mrgreen:

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Re: APOD: Comet Clark is near the Edge (2017 May 27)

Post by Ann » Sat May 27, 2017 6:05 pm

neufer wrote:
Ann wrote:
Ever seen Green Lantern wearing a cape? I haven't! And what is the tail of a comet, if not the superhero's cape?
https://en.wikipedia.org/wiki/Alan_Scott wrote: <<The original Green Lantern was created by an American artist named Martin Nodell. Nodell mentions Richard Wagner's opera cycle The Ring of the Nibelung and the sight of a trainman's green railway lantern as his inspiration. After seeing this opera, Nodell sought to create a superhero who wielded a variety of magical powers from a magic ring, which he regularly recharged from a green lantern. Nodell wanted a colorful and interesting costume for his character, deriving from elements of Greek mythology.
Image
Franklin D Roosevelt, giving off a
green glow from his head.
Mary Poppins, flying and scattering green (and pink and blue)
stuff from her magical umbrella.
Okay, okay! Goodness! If you are going to go back that far, maybe Comet Clark is really Franklin D Roosevelt from 1940, caught in a time loop and flying around in his magical wheelchair, while his head is giving off a green glow!

On the other hand, why do the boys get to have all the fun? Who's to say that green little superhero comet isn't Mary Poppins in disguise, propelling herself skywards with her magical (and a lot greener than you'd think) umbrella?

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Re: APOD: Comet Clark is near the Edge (2017 May 27)

Post by neufer » Sat May 27, 2017 6:37 pm

Ann wrote:
On the other hand, why do the boys get to have all the fun? Who's to say that green little superhero comet isn't Mary Poppins in disguise, propelling herself skywards with her magical (and a lot greener than you'd think) umbrella?
  • That would be practically perfect in every way:
https://en.wikipedia.org/wiki/Comet wrote:
Click to play embedded YouTube video.
<<Cometary nuclei are composed of an amalgamation of rock, dust, water ice, and frozen gases such as carbon dioxide, carbon monoxide, methane, and ammonia. As such, they are popularly described as "dirty snowballs" after Fred Whipple's model. However, some comets may have a higher dust content, leading them to be called "icy dirtballs". Research conducted in 2014 suggests that comets are like "deep fried ice cream", in that their surfaces are formed of dense crystalline ice mixed with organic compounds, while the interior ice is colder and less dense.

The surface of the nucleus is generally dry, dusty or rocky, suggesting that the ices are hidden beneath a surface crust several metres thick. In addition to the gases already mentioned, the nuclei contain a variety of organic compounds, which may include methanol, hydrogen cyanide, formaldehyde, ethanol, and ethane and perhaps more complex molecules such as long-chain hydrocarbons and amino acids. In 2009, it was confirmed that the amino acid glycine had been found in the comet dust recovered by NASA's Stardust mission. In August 2011, a report, based on NASA studies of meteorites found on Earth, was published suggesting DNA and RNA components (adenine, guanine, and related organic molecules) may have been formed on asteroids and comets.

The outer surfaces of cometary nuclei have a very low albedo, making them among the least reflective objects found in the Solar System. The Giotto space probe found that the nucleus of Halley's Comet reflects about four percent of the light that falls on it, and Deep Space 1 discovered that Comet Borrelly's surface reflects less than 3% of the light that falls on it [and comet 67P/Churyumov–Gerasimenko about six percent]; by comparison, asphalt reflects seven percent. The dark surface material of the nucleus may consist of complex organic compounds. Solar heating drives off lighter volatile compounds, leaving behind larger organic compounds that tend to be very dark, like tar or crude oil. The low reflectivity of cometary surfaces causes them to absorb the heat that drives their outgassing processes.>>
Art Neuendorffer

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Re: APOD: Comet Clark is near the Edge (2017 May 27)

Post by Boomer12k » Sun May 28, 2017 3:59 am

That is just a STUNNING image....thanks!!!

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