APOD: Three Planets and a Comet (2021 Dec 23)

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APOD: Three Planets and a Comet (2021 Dec 23)

Post by APOD Robot » Thu Dec 23, 2021 5:06 am

Image Three Planets and a Comet

Explanation: Are you still looking for that perfect holiday gift for an astronomer? If your night sky is dark and horizon clear enough, the Solar System may have done your shopping for you. Send them outside after sunset to see three planets and a comet. In this snapshot of the December solstice evening sky from the village of Kirazli, Turkey the brightest celestial beacon is Venus, close to the southwestern horizon at the right. Look left and up to find Saturn shining between clouds. Follow that line farther left and up to bright Jupiter, the Solar System's ruling gas giant. This year's surprise visitor to the inner Solar System, Comet Leonard (C/2021 A1), is near the horizon too. The comet is fainter but forms a nearly equilateral triangle with planets Venus and Saturn in this view. After a dramatic brightening in recent days the comet is just visible to the unaided eye, though a nice pair of binoculars is always a good idea.

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Re: APOD: Three Planets and a Comet (2021 Dec 23)

Post by orin stepanek » Thu Dec 23, 2021 12:24 pm

20211221Tezel.jpg
Nice!
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Re: APOD: Three Planets and a Comet (2021 Dec 23)

Post by bls0326 » Thu Dec 23, 2021 1:50 pm

I looked for the comet the evening of Dec. 16th. I probably saw it, but never could identify it. The planets were obvious and I knew about where to look. I was in a fairly dark area with a set of binoculars and a monocular, 10X to 15X.

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Re: APOD: Three Planets and a Comet (2021 Dec 23)

Post by Chris Peterson » Thu Dec 23, 2021 2:35 pm

orin stepanek wrote: Thu Dec 23, 2021 12:24 pm 20211221Tezel.jpg
Nice!
Yeah, it's subtle in a wide angle shot in a twilight sky! I shot this a few nights ago. Venus, Saturn, and the comet are all there. Can you see the latter?
_
_7_49626.jpg
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Re: APOD: Three Planets and a Comet (2021 Dec 23)

Post by gvann » Thu Dec 23, 2021 2:45 pm

Correction: There are four planets in the picture. Indeed, planet Earth occupies a large part of the frame. And I might argue that, artistically, the picture of Earth rivals the picture of the sky. It would be worth framing even by itself. Thank you, Mr. Tezel.

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Re: APOD: Three Planets and a Comet (2021 Dec 23)

Post by neufer » Thu Dec 23, 2021 3:36 pm

APOD Robot wrote: Thu Dec 23, 2021 5:06 am
Explanation: Are you still looking for that perfect holiday gift for an astronomer? ... In this snapshot of the December solstice evening sky from the village of Kirazli, Turkey the brightest celestial beacon is Venus, close to the southwestern horizon at the right. Look left and up to find Saturn shining between clouds. Follow that line farther left and up to bright Jupiter, the Solar System's ruling gas giant. This year's surprise visitor to the inner Solar System, Comet Leonard (C/2021 A1), is near the horizon too. The comet is fainter but forms a nearly equilateral triangle with planets Venus and Saturn in this view. After a dramatic brightening in recent days the comet is just visible to the unaided eye, though a nice pair of binoculars is always a good idea.
https://en.wikipedia.org/wiki/Three_Men_and_a_Baby wrote:


<<Three Men and a Baby is a 1987 American comedy film directed by Leonard Nimoy. It stars Tom Selleck, Steve Guttenberg, and Ted Danson as three bachelors as they attempt to adapt their lives to de facto fatherhood with the arrival of the love child of one of the gentlemen.

Architect Peter Mitchell, satirist Michael Kellam, and actor Jack Holden are happy bachelors in their shared NYC apartment, with frequent parties and flings. One day, a baby named Mary arrives on their doorstep with a note revealing she is the result of Jack’s tryst with an actress named Sylvia during a Stratford Festival Shakespearean production a year prior. Jack is in Turkey shooting a movie, and obliges a director friend's favor to have a package delivered to the apartment. Jack asks his roommates to keep the delivery a secret per his friend's wishes; when Mary arrives, they believe she is the “package.” Peter and Michael are totally befuddled how to care for Mary, and Peter leaves to buy supplies. Their landlady Mrs. Hathaway delivers a small box – the actual "package" of heroin – which Michael tosses aside. They learn to care for Mary, including diaper changes, baths, and feedings.

Four days later, two drug dealers arrive at the apartment for the package. Peter and Michael mistakenly give them Mary, along with a can of powdered milk the dealers believe is the heroin. Peter discovers the actual package; realizing the mix-up, he runs downstairs but trips, spilling the package's contents. He gathers up the drugs and confronts the men outside, causing a scuffle. A police officer on horseback intervenes; Peter rescues Mary, but the dealers flee with the can of powdered milk. The officer detains Peter and Michael at the apartment until Sgt. Melkowitz, a narcotics officer, arrives to question them. Jack calls from Turkey, but Peter and Michael are unable to talk openly as they are being recorded.>>
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Re: APOD: Three Planets and a Comet (2021 Dec 23)

Post by De58te » Thu Dec 23, 2021 4:32 pm

Neufer, that's a nice gift for a non astronomer like me, but who watches a lot of space shows on TV like Star Trek. Three of my favorite television actors appeared in that film. My favorite is Tom Selleck who in my opinion can do no wrong. Every performance he does is memorable. Followed by a close second is Ted Danson. Cheers would never have been such a classic without Danson. And of course third goes to the director Leonard Nimoy who played the best Vulcan ever on Star Trek. No other Vulcan even comes close. Oh and Steve Guttenberg was alright too, even though I don't know what happened to him in the past 20 years.

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Re: APOD: Three Planets and a Comet (2021 Dec 23)

Post by neufer » Thu Dec 23, 2021 4:56 pm

De58te wrote: Thu Dec 23, 2021 4:32 pm
Neufer, that's a nice gift for a non astronomer like me, but who watches a lot of space shows on TV like Star Trek. Three of my favorite television actors appeared in that film. My favorite is Tom Selleck who in my opinion can do no wrong.
Click to play embedded YouTube video.
  • None that he would admit to, at least:
https://en.wikipedia.org/wiki/Tom_Selleck#2015_Water_controversy wrote:
<<Thomas William Selleck (born January 29, 1945) was sued by the Calleguas Municipal Water District for allegedly improperly transferring approximately 1.4 million gallons of water from the Calleguas Municipal Water District to the Hidden Valley Municipal Water District during the driest California drought since record-keeping began, which he used to water his avocado farm. He settled the suit by paying $21,685.55 to the Calleguas Municipal Water District, an amount which represented the district's private investigator fees in connection with the case. By settling, Selleck avoided a trial while simultaneously not admitting to any fault or wrongdoing.>>
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Re: APOD: Three Planets and a Comet (2021 Dec 23)

Post by beryllium732 » Thu Dec 23, 2021 6:19 pm

What's the red spot to the left of the comet?

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Re: APOD: Three Planets and a Comet (2021 Dec 23)

Post by canopia » Thu Dec 23, 2021 7:14 pm

beryllium732 wrote: Thu Dec 23, 2021 6:19 pm What's the red spot to the left of the comet?
That was a plane, moving a short distance during the 4-second exposure.

Tunç Tezel

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Re: APOD: Three Planets and a Comet (2021 Dec 23)

Post by neufer » Thu Dec 23, 2021 8:31 pm

canopia wrote: Thu Dec 23, 2021 7:14 pm
beryllium732 wrote: Thu Dec 23, 2021 6:19 pm
What's the red spot to the left of the comet?
That was a plane, moving a short distance during the 4-second exposure. - Tunç Tezel
https://en.wikipedia.org/wiki/Casimir_effect wrote:
Click to play embedded YouTube video.

<<In quantum field theory, the Casimir effect is a physical force acting on the macroscopic boundaries of a confined space which arises from the quantum fluctuations of the field. It is named after the Dutch physicist Hendrik Casimir, who predicted the effect for electromagnetic systems in 1948. In the same year, Casimir together with Dirk Polder described a similar effect experienced by a neutral atom in the vicinity of a macroscopic interface which is referred to as Casimir–Polder force. Their result is a generalization of the London–van der Waals force and includes retardation due to the finite speed of light. Since the fundamental principles leading to the London–van der Waals force, the Casimir and the Casimir–Polder force, respectively, can be formulated on the same footing, the distinction in nomenclature nowadays serves a historical purpose mostly and usually refers to the different physical setups. It was not until 1997 that a direct experiment by S. Lamoreaux quantitatively measured the Casimir force to within 5% of the value predicted by the theory.

The Casimir effect can be understood by the idea that the presence of macroscopic material interfaces, such as conducting metals and dielectrics, alters the vacuum expectation value of the energy of the second-quantized electromagnetic field. Since the value of this energy depends on the shapes and positions of the materials, the Casimir effect manifests itself as a force between such objects. Any medium supporting oscillations has an analogue of the Casimir effect. For example, beads on a string as well as plates submerged in turbulent water or gas illustrate the Casimir force. In modern theoretical physics, the Casimir effect plays an important role in the chiral bag model of the nucleon; in applied physics it is significant in some aspects of emerging microtechnologies and nanotechnologies.>>
Art Neuendorffer

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Re: APOD: Three Planets and a Comet (2021 Dec 23)

Post by orin stepanek » Thu Dec 23, 2021 9:02 pm

Chris Peterson wrote: Thu Dec 23, 2021 2:35 pm
orin stepanek wrote: Thu Dec 23, 2021 12:24 pm 20211221Tezel.jpg
Nice!
Yeah, it's subtle in a wide angle shot in a twilight sky! I shot this a few nights ago. Venus, Saturn, and the comet are all there. Can you see the latter?
_
_7_49626.jpg
Oh my It ts very difficult to see; Let alone that it is a Comet that we are looking at! :shock: :lol2:
Orin

Smile today; tomorrow's another day!

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Re: APOD: Three Planets and a Comet (2021 Dec 23)

Post by canopia » Thu Dec 23, 2021 9:05 pm

Good call Neufer, remembering it is Festivus today. :ssmile:

Tunç
neufer wrote: Thu Dec 23, 2021 8:31 pm
canopia wrote: Thu Dec 23, 2021 7:14 pm
beryllium732 wrote: Thu Dec 23, 2021 6:19 pm
What's the red spot to the left of the comet?
That was a plane, moving a short distance during the 4-second exposure. - Tunç Tezel
https://en.wikipedia.org/wiki/Casimir_effect wrote:
Click to play embedded YouTube video.

<<In quantum field theory, the Casimir effect is a physical force acting on the macroscopic boundaries of a confined space which arises from the quantum fluctuations of the field. It is named after the Dutch physicist Hendrik Casimir, who predicted the effect for electromagnetic systems in 1948. In the same year, Casimir together with Dirk Polder described a similar effect experienced by a neutral atom in the vicinity of a macroscopic interface which is referred to as Casimir–Polder force. Their result is a generalization of the London–van der Waals force and includes retardation due to the finite speed of light. Since the fundamental principles leading to the London–van der Waals force, the Casimir and the Casimir–Polder force, respectively, can be formulated on the same footing, the distinction in nomenclature nowadays serves a historical purpose mostly and usually refers to the different physical setups. It was not until 1997 that a direct experiment by S. Lamoreaux quantitatively measured the Casimir force to within 5% of the value predicted by the theory.

The Casimir effect can be understood by the idea that the presence of macroscopic material interfaces, such as conducting metals and dielectrics, alters the vacuum expectation value of the energy of the second-quantized electromagnetic field. Since the value of this energy depends on the shapes and positions of the materials, the Casimir effect manifests itself as a force between such objects. Any medium supporting oscillations has an analogue of the Casimir effect. For example, beads on a string as well as plates submerged in turbulent water or gas illustrate the Casimir force. In modern theoretical physics, the Casimir effect plays an important role in the chiral bag model of the nucleon; in applied physics it is significant in some aspects of emerging microtechnologies and nanotechnologies.>>

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Re: APOD: Three Planets and a Comet (2021 Dec 23)

Post by neufer » Thu Dec 23, 2021 9:26 pm

canopia wrote: Thu Dec 23, 2021 9:05 pm
Good call Neufer, remembering it is Festivus today. :ssmile:
Tunç
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