APOD: Venus Just After Sunset (2010 Oct 20)

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APOD: Venus Just After Sunset (2010 Oct 20)

Post by APOD Robot » Wed Oct 20, 2010 3:58 am

Image Venus Just After Sunset

Explanation: Is that Venus or an airplane? A common ponderable for sky enthusiasts is deciding if that bright spot near the horizon is the planet Venus. Usually, an airplane will show itself by moving significantly in a few moments. Venus will set only slowly as the Earth turns. Still, the identification would be easier if Venus did not keep shifting its position each night. Pictured above, Venus was captured on 44 different nights during 2006 and 2007 over the Bolu mountains in Turkey, when Earth's sister planet appeared exclusively in the evening sky. The average spacing of the images was about five days, while the images were always taken with the Sun about seven degrees below the horizon. That bright spot toward the west in your evening sky this month might be neither Venus nor an airplane, but Mars.

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Re: APOD: Venus Just After Sunset (2010 Oct 20)

Post by León » Wed Oct 20, 2010 10:18 am

APOD - Astronomy Picture of the Day Günün Gökbilim Görüntüsü In Turkish nickname on the image said
In December 2006, evening sky, Venus is emerging, steadily rising from last day as the people began to stay in the sky for a long time. Venus rising until May 2007, but also significantly shifted to the southwest to the northwest. This situation changed in mid-May. Observed a significant change after a two-week Venus began to descend gradually. June, growing at a pace of low planet, sets in earlier in the month of July when it came to depend on every day, for 3 minutes. Already the end of July in the evening sky began izlenememeye. http://www.bulutsu.org/ggg/

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Re: APOD: Venus Just After Sunset (2010 Oct 20)

Post by biddie67 » Wed Oct 20, 2010 1:02 pm

An awesome project that extended over 200 days - Kudos to Tunç Tezel !!

It would be interesting to see an animation of the relative positions of Venus and Earth in their orbits that generated the visual effect captured here on Earth.

Are their relative orbits slightly inclined to each other ?

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Re: APOD: Venus Just After Sunset (2010 Oct 20)

Post by rstevenson » Wed Oct 20, 2010 1:16 pm

biddie67 wrote:It would be interesting to see an animation of the relative positions of Venus and Earth in their orbits that generated the visual effect captured here on Earth.

Are their relative orbits slightly inclined to each other ?
Venus' orbit is inclined to the Earth's by about 3°, if memory serves. Like you, I wanted to see the orbit animated. I just found a quite good page showing several views of the orbit and how it appears in Earth's sky, and why. Alas, it's an astrology site, not an astronomy one -- but you don't have to pay attention to what they're saying; just have a look at the animations. They were produced using astronomy software, so I assume they're correct.

Rob

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Re: APOD: Venus Just After Sunset (2010 Oct 20)

Post by orin stepanek » Wed Oct 20, 2010 1:27 pm

I found this in the links. Something about silhouettes really is just beautiful. Today's picture is also great. 8-) :D
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Van der Pol oscillator with εα ~ 0.025

Post by neufer » Wed Oct 20, 2010 2:27 pm

http://www.scholarpedia.org/article/Duffing_oscillator wrote: Duffing oscillator is an example of a periodically forced
oscillator with a nonlinear elasticity, written as:

where the damping constant obeys δ ≥ 0, and it is also known as
a simple model which yields chaos, as well as van der Pol oscillator.

For ß >0, the Duffing oscillator can be interpreted as a forced oscillator
with a spring whose restoring force is written as Image

When α >0, this spring is called a hardening spring, and,

when α <0, it is called a softening spring [or simple
pendulum (e.g., Prometheus w/periodic F-ring forcing)]
.


The response of the Duffing oscillator to a weak periodic forcing:
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Re: APOD: Venus Just After Sunset (2010 Oct 20)

Post by Ann » Wed Oct 20, 2010 3:10 pm

Wow, Art. I'm sure impressed with you math guys. And I think the Duffing oscillator graphs are quite beautiful, and I can see that Venus appears to trace what looks like a Duffing oscillator in the sky. Today's APOD is quite interesting, by the way.

And Orin, I love the picture you posted. But what is that elongated orangish streak on the right?
Click to play embedded YouTube video.
Mars Attacks?

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Re: APOD: Venus Just After Sunset (2010 Oct 20)

Post by emc » Wed Oct 20, 2010 3:20 pm

Thanks Ann! I need you to explain Art sometimes. I didn't get the connection. Now it's obvious. 8-)
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Re: APOD: Venus Just After Sunset (2010 Oct 20)

Post by neufer » Wed Oct 20, 2010 3:51 pm

emc wrote:Thanks Ann! I need you to explain Art sometimes. I didn't get the connection. Now it's obvious. 8-)
http://www.thedailyshow.com/watch/mon-o ... ding-smart
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Re: APOD: Venus Just After Sunset (2010 Oct 20)

Post by emc » Wed Oct 20, 2010 4:13 pm

Thanks Art! Now your helping too! Blyme... this is a good day!
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Re: APOD: Venus Just After Sunset (2010 Oct 20)

Post by biddie67 » Wed Oct 20, 2010 4:28 pm

Blyme, for sure !!! Within a mere 9 comments, a wonderous abstract correlation has appeared among the patterns of Venus in a photo, a blue-lined graph of that impossible Duffing oscillator and astrology's retrograde path #2.

BTW, it seems that today's picture might be an example of retrograde path #2 caught in the act?
Last edited by biddie67 on Wed Oct 20, 2010 4:29 pm, edited 1 time in total.

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Re: APOD: Venus Just After Sunset (2010 Oct 20)

Post by Daniel Fischer » Wed Oct 20, 2010 4:28 pm

The final sentence of the caption makes no sense as even the "Mars" link itself makes clear: That planet is so faint and so close to the Sun now that it takes some effort (including binoculars) to even locate it. Which would only work for low Northern or Southern latitudes anyway: For mid-Northern latitudes there have been no planets in the Western evening sky for some time already. And where the ecliptic is steep enogh, it's certainly Venus that you're seeing if there's a "bright spot toward the west". As evidence here are two views of the Western dusk sky from Sep. 29 at 37° North, a wide view and a close-up of Venus & Mercury; the situation has further 'deteriorated' since then.

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Re: APOD: Venus Just After Sunset (2010 Oct 20)

Post by Axel » Wed Oct 20, 2010 7:31 pm

Is the inflection point at the top of the curve the position of Venus at its maximum elongation from the Sun, around 9 June 2007? Nothing else seems to make sense considering the time span involved.

Duffing oscillator - a brilliant analogical flash! Thanks for that.

Mr Stevenson, why the "Alas"? You are surprised astrologers use astronomy?

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Re: APOD: Venus Just After Sunset (2010 Oct 20)

Post by durant1928 » Wed Oct 20, 2010 8:18 pm

Is there a technical name for the geometric figure traced by the multiple photos of Venus ?

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Re: APOD: Venus Just After Sunset (2010 Oct 20)

Post by bystander » Wed Oct 20, 2010 8:47 pm

Axel wrote:You are surprised astrologers use astronomy?
I am surprised present day astrologers even know what astronomy is.

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Re: APOD: Venus Just After Sunset (2010 Oct 20)

Post by mexhunter » Wed Oct 20, 2010 9:52 pm

The picture seems charming.
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Re: APOD: Venus Just After Sunset (2010 Oct 20)

Post by orin stepanek » Wed Oct 20, 2010 10:53 pm

Ann wrote:
And Orin, I love the picture you posted. But what is that elongated orangish streak on the right?

Mars Attacks?

Ann
Hi Ann; I can tell; you're a Sci Fi fan! 8-) I think the orange is from the sunset. :)
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Re: APOD: Venus Just After Sunset (2010 Oct 20)

Post by rstevenson » Thu Oct 21, 2010 2:41 am

Axel wrote:Mr Stevenson, why the "Alas"? You are surprised astrologers use astronomy?
I'm not surprised that people misuse tools, no. But that's not what the "Alas" implied. It implied a sense of resignation that one had to go to a non-scientific page to get good illustrations of the motions of the planet under discussion. Of course I realize it was likely not absolutely necessary to go there, but that link came up in the top half of page 1 in Google when I searched, and it was really the lack of good clear illustrations from science sites appearing high in the search listings that prompted the "Alas."

I hope that clarifies my choice of words.

Rob

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Re: APOD: Venus Just After Sunset (2010 Oct 20)

Post by Ann » Thu Oct 21, 2010 3:36 am

orin stepanek wrote:
Ann wrote:
And Orin, I love the picture you posted. But what is that elongated orangish streak on the right?

Mars Attacks?

Ann
Hi Ann; I can tell; you're a Sci Fi fan! 8-) I think the orange is from the sunset. :)
Yeah well, I'm not as much a fan as I used to be.

Do you really think that thing is caused by the sunset? It really does look a bit like it might be Mars which has suddenly launched itself at us! :shock:

Rob, I agree with what you said about astronomy and astrology. Personally I think that astrology uses astronomy as an unexplained illustration of astrology (such as, if you want to know how Venus is going to influence your future love life, just look at this apparent path that Venus traces out on the sky).

When I tell people that I'm into astronomy, I've occasionally been asked questions like whether I think that a Leo might be compatible with a Libra.

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Re: APOD: Venus Just After Sunset (2010 Oct 20)

Post by orin stepanek » Thu Oct 21, 2010 4:04 am

Ann wrote:
orin stepanek wrote:
Ann wrote:
And Orin, I love the picture you posted. But what is that elongated orangish streak on the right?

Mars Attacks?

Ann
Hi Ann; I can tell; you're a Sci Fi fan! 8-) I think the orange is from the sunset. :)
Yeah well, I'm not as much a fan as I used to be.

Do you really think that thing is caused by the sunset? It really does look a bit like it might be Mars which has suddenly launched itself at us! :shock:

Ann
I brought the link up again. I was looking at the orange at the bottom right. The one in the sky is an airplane according to the write up. Looks like it's motion got it stretched out.
BTW; this looks more like an attack! :mrgreen:
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Re: APOD: Venus Just After Sunset (2010 Oct 20)

Post by BMAONE23 » Thu Oct 21, 2010 1:52 pm

Orin,
I think Ann is refering to the streak on the right side of the image about half way up the image

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Re: APOD: Venus Just After Sunset (2010 Oct 20)

Post by Axel » Thu Oct 21, 2010 2:23 pm

bystander wrote:
Axel wrote:You are surprised astrologers use astronomy?
I am surprised present day astrologers even know what astronomy is.
Think again.
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Re: APOD: Venus Just After Sunset (2010 Oct 20)

Post by rstevenson » Thu Oct 21, 2010 2:51 pm

I apologize for starting to derail the topic by making that remark about astrology -- which, as we all know, we cannot discuss here at the Asterisk*. Perhaps I can get us back on topic by suggesting that any astrologer who has been attracted to this discussion instead rush right over to the One Million Dollar Paranormal Challenge site, and there make application as instructed. All you have to do is make a verifiable, testable, specific claim based on astrology, and if your claim is true you will become richer by $1M! When you collect your check, please come back here and announce your success, and I will be the first in line to offer my most sincere apology.

Rob

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Re: APOD: Venus Just After Sunset (2010 Oct 20)

Post by Chris Peterson » Thu Oct 21, 2010 2:57 pm

bystander wrote:I am surprised present day astrologers even know what astronomy is.
It is important to remember that astrology is a kind of religion; you can be an astrologer and still know something about astronomy. The science of astronomy originated from the religion of astrology. Since astrology is all about the positions of astronomical objects, we find much ancient astrological influence in positional astronomy. Modern astrologers make use of planetarium programs designed for astronomy.

While the names (astronomy and astrology) as similar enough to be confusing to many people, the two subjects have virtually nothing in common, of course- even if astrologers sometimes use astronomical tools.
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Re: APOD: Venus Just After Sunset (2010 Oct 20)

Post by neufer » Thu Oct 21, 2010 3:26 pm

Chris Peterson wrote:
bystander wrote:
I am surprised present day astrologers even know what astronomy is.
It is important to remember that astrology is a kind of religion; you can be an astrologer and still know something about astronomy. The science of astronomy originated from the religion of astrology. Since astrology is all about the positions of astronomical objects, we find much ancient astrological influence in positional astronomy. Modern astrologers make use of planetarium programs designed for astronomy.

While the names (astronomy and astrology) as similar enough to be confusing to many people, the two subjects have virtually nothing in common, of course- even if astrologers sometimes use astronomical tools.
Astrology, n. [F. astrologie, L. astrologia, star + discourse, to speak.] In its etymological signification, the science of the stars; among the ancients, synonymous with astronomy; subsequently, the art of judging of the influences of the stars upon human affairs, and of foretelling events by their position and aspects. Astrology was much in vogue during the Middle Ages, and became the parent of modern astronomy, as alchemy did of chemistry. It was divided into two kinds: judicial astrology, which assumed to foretell the fate and acts of nations and individuals, and natural astrology, which undertook to predict events of inanimate nature, such as changes of the weather, etc.
----------------------------------
Nomad, n. [L. nomas, -adis, Gr. , , pasturing, roaming without fixed home, fr. a pasture, allotted abode, fr. to distribute, allot, drive to pasture; prob. akin to AS. niman to take, and E. nimble: cf. F. nomade. Cf. Astronomy, Economy, Nimble, Nemesis, Numb, Number.]
One of a race or tribe that has no fixed location, but wanders from place to place in search of pasture or game.
----------------------------------
Astronomy, n. [OE. astronomie, F. astronomie, L. astronomia, fr. Gr. ,
fr. astronomer; star + to distribute, regulate. See Star, and Nomad.]

1. Astrology. [Obs.]
    • Sonnet 14
    Not from the stars do I my judgment pluck;
    And yet methinks I have astronomy,
    But not to tell of good or evil luck,
    Of plagues, of dearths, or seasons' quality;
    Nor can I fortune to brief minutes tell,
    Pointing to each his thunder, rain and wind,
    Or say with princes if it shall go well,
    By oft predict that I in heaven find:
    But from thine eyes my knowledge I derive,
    And, constant stars, in them I read such art
    As truth and beauty shall together thrive,
    If from thyself to store thou wouldst convert;
    . Or else of thee this I prognosticate:
    . Thy end is truth's and beauty's doom and date.
2. The science which treats of the celestial bodies, of their magnitudes, motions, distances, periods
of revolution, eclipses, constitution, physical condition, and of the causes of their various phenomena.

3. A treatise on, or text-book of, the science. Physical astronomy.
----------------------------------
Art Neuendorffer

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