APOD: Crescent Venus and Moon (2010 May 16)

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APOD: Crescent Venus and Moon (2010 May 16)

Post by APOD Robot » Sun May 16, 2010 3:56 am

Image Crescent Venus and Moon

Explanation: There's something behind these clouds. Those faint graceful arcs, upon inspection, are actually far, far in the distance. They are the Earth's Moon and the planet Venus. Both the Moon and Venus are bright enough to be seen during the day, and both are quite capable of showing a crescent phase. To see Venus, which appears quite small, in a crescent phase requires binoculars or a telescope. In the above dramatic daytime image taken from Budapest, Hungary in 2004, the Moon and Venus shared a similar crescent phase a few minutes before the Moon eclipsed the larger but more distant world. Similarly, visible today in parts of Africa and Asia, a crescent Moon will again eclipse Venus during the day. About an hour after the above image was taken, Venus reappeared.

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Re: APOD: Crescent Venus and Moon (2010 May 16)

Post by BMAONE23 » Sun May 16, 2010 4:19 am

This is a great image to show the relative angular size of Venus at near closest approach. Compared to the size of the Moon, Venus appears quite large though not very bright. Similar to my avatar which depicts the oppositions of Mars, Jupiter and Saturn in close conjunction with the moon
Image

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Re: APOD: Crescent Venus and Moon (2010 May 16)

Post by neufer » Sun May 16, 2010 4:38 am

http://en.wikipedia.org/wiki/Croissant wrote:
<< A Kipferl: precursor to the Croissant
Image
The kipferl - ancestor of the croissant - has been documented in Austria going back at least as far as the 13th century, in various shapes. The kipferl can be made plain or with nut or other fillings. Fanciful stories of how the kipfel was created are culinary legends, at least one going back to the 19th century. These include tales that it was invented in Europe to celebrate the defeat of a Muslim invasion at the decisive Battle of Tours by the Franks in 732, with the shape representing the Islamic crescent; that it was invented in Vienna, Austria in 1683 to celebrate the defeat of the Turks to Polish forces in the Turkish siege of the city, as a reference to the crescents on the Turkish flags, when bakers staying up all night heard the tunneling operation and gave the alarm; tales linking croissants with the kifli and the siege of Buda[pest] in 1686; and those detailing Marie Antoinette's hankering after a Polish specialty.

Image
The "birth" of the croissant itself - that is, its adaptation from the plainer form of kipferl, before its subsequent evolution (to a puff pastry) - can be dated with some precision to at latest 1839, when an Austrian artillery officer, August Zang, founded a Viennese Bakery ("Boulangerie Viennoise") at 92, rue de Richelieu in Paris. This bakery, which served Viennese specialties including the kipfel and the Vienna loaf, quickly became popular and inspired French imitators. August Zang himself returned to Austria in 1848 to become a press magnate, but the bakery remained popular for some time after.>>
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Re: APOD: Crescent Venus and Moon (2010 May 16)

Post by Beyond » Sun May 16, 2010 5:38 am

What an amazing illustration of -- Big and Little. However, I'm wondering if the picture has been reversed? I've seen many crescents of the moon and do not remember any crescents being on the left side. Maybe all the ones i have seen has been when the moon is waxing and not waneing.
Tonight i caught the second day after a new moon and the slim crescent was on the right side. I'm going to have to check into this if the weather co-operates and i don't forget.

Perhaps our Great Quotationist can --ahem-- shed a little light on this?
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Re: APOD: Crescent Venus and Moon (2010 May 16)

Post by Czerno » Sun May 16, 2010 9:09 am

beyond wrote: I've seen many crescents of the moon and do not remember any crescents being on the left side. Maybe all the ones i have seen has been when the moon is waxing and not waneing.
Not the Great Quotationist either ;=) but in his absence, the Moon looks like a "C" open to the right when it's phase is "D"ecreasing - what today's APOD is showing - while a "C"rescent proper (inCreasing) looks to the left, like letter "D".
Easily remembered : Crescent (inCreasing) moon -> D ; Decrecent moon -> C .

I prefer not to comment on the fact that anybody, but a little child, can still have to ask such a question.

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Re: APOD: Crescent Venus and Moon (2010 May 16)

Post by Case » Sun May 16, 2010 9:27 am

Czerno wrote:Easily remembered : Crescent (inCreasing) moon -> D ; Decrecent moon -> C .
That is such a hemisphere-centric answer... :wink:
http://www.math.nus.edu.sg/aslaksen/app ... cmoon.html

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Re: APOD: Crescent Venus and Moon (2010 May 16)

Post by owlice » Sun May 16, 2010 9:36 am

Case, that's a very cool link; thanks for it!
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Re: APOD: Crescent Venus and Moon (2010 May 16)

Post by Beyond » Sun May 16, 2010 11:50 am

Besides the fact that there are a few kids that peruse this site that would ask if the moon is ever left faceing, you have to realize that there are some of us who tend to get "brain" freeze around 2:00am. This, plus haveing to deal with toooo much Kipferl, could throw anyone a bit off.
Its a good thing that it is well known that there is no such thing as a "dumb" question, or sometimes we could all be in trouble.

With that said, now i have to go and finish wakeing up.
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Re: APOD: Crescent Venus and Moon (2010 May 16)

Post by biddie67 » Sun May 16, 2010 12:19 pm

Case - yes! a really great link - I played with it for quite a while ....

P.S. forgot to add - today's APOD is not only beautiful but very interesting.

Quigley

Re: APOD: Crescent Venus and Moon (2010 May 16)

Post by Quigley » Sun May 16, 2010 2:47 pm

I was wondering why the planet Venus appears brighter and more crisp than the closer crescent moon in this image?

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Re: APOD: Crescent Venus and Moon (2010 May 16)

Post by neufer » Sun May 16, 2010 3:04 pm

Quigley wrote:I was wondering why the planet Venus appears brighter and more crisp than the closer crescent moon in this image?
Sun-Moon-Earth triangle and Sun-Venus-Earth triangle are NOT similar.

They basically share one side & one angle but that is all.

The Sun-Moon-Earth angle will always be greater than the Sun-Venus-Earth angle
during a Moon-Venus conjunction and hence the moon's crescent will always be thinner.

Large Sun-Moon-Earth angles are particularly detrimental to the Moon's
(initially very low) albedo because rocks & topography cast long shadows.
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Re: APOD: Crescent Venus and Moon (2010 May 16)

Post by BMAONE23 » Mon May 17, 2010 12:17 am

When you view the Moon from the northern hemisphere, It traverses the southern sky and waxes from the right to the left.
When you view the moon from the southern hemisphere, It traverses the northern sky and waxes from the left to the right.

RET

Re: APOD: Crescent Venus and Moon (2010 May 16)

Post by RET » Mon May 17, 2010 3:11 pm

I think this photo was taken 'after' the eclipse, not 'before' as told in the explanation.

I suppose that the event occurred May 21, 2004. The moonage of the day was about 2. So, the moon should be moving to the right (in this image).
A computer simulation gives me the same answer.

Do I make some mistakes?

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Re: APOD: Crescent Venus and Moon (2010 May 16)

Post by neufer » Mon May 17, 2010 3:47 pm

RET wrote:I think this photo was taken 'after' the eclipse, not 'before' as told in the explanation.

I suppose that the event occurred May 21, 2004. The moonage of the day was about 2.
So, the moon should be moving to the right (in this image).
A computer simulation gives me the same answer.

Do I make some mistakes?
You are correct (assuming that it is May 21, 2004).

(Did they print to photo upside down?)
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Re: APOD: Crescent Venus and Moon (2010 May 16)

Post by Guest » Thu May 20, 2010 6:57 am

Hi,
neufer wrote:
RET wrote:I think this photo was taken 'after' the eclipse, not 'before' as told in the explanation.

I suppose that the event occurred May 21, 2004. The moonage of the day was about 2.
So, the moon should be moving to the right (in this image).
A computer simulation gives me the same answer.

Do I make some mistakes?
You are correct (assuming that it is May 21, 2004).

(Did they print to photo upside down?)
Thanks. I asked an editor about this, and got a reply that the date is correct. He/She also thought that it was 'after'.

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Crescent Venus and moon

Post by Lohrenz » Sat May 22, 2010 7:35 pm

Hi all

That picture of the two crescents has me confused. Is it a crescent old moon and this picture was taen at dawn? Was it a crescent new moon seen upside down and inverted - as in astronomical telescope? Maybe I'm just thick! Someone please tell me how it works!

MikeyMike

Re: APOD: Crescent Venus and Moon (2010 May 16)

Post by MikeyMike » Sat May 05, 2012 5:47 am

Incredibly cool looking, but unfortunately phony. I was suckered in by it myself, until a friend pointed out if you download it then zoom in close on Venus you can tell by the pixelated square around it that it's been pasted in. :(

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Re: APOD: Crescent Venus and Moon (2010 May 16)

Post by bystander » Sat May 05, 2012 6:12 am

If you zoom any image past its native resolution, it will become pixelated.
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Re: APOD: Crescent Venus and Moon (2010 May 16)

Post by geckzilla » Sat May 05, 2012 1:41 pm

MikeyMike wrote:Incredibly cool looking, but unfortunately phony. I was suckered in by it myself, until a friend pointed out if you download it then zoom in close on Venus you can tell by the pixelated square around it that it's been pasted in. :(
It's not phony. It looks to me like Venus has been sharpened, but it does not look phony at all to me. You have to keep in mind that JPEG artifacts also produce square-like structures which become more apparent when one zooms in on them, as well. Think before you accuse.
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Re: APOD: Crescent Venus and Moon (2010 May 16)

Post by rstevenson » Sat May 05, 2012 2:54 pm

Not to mention the fact that there is no "pixelated square around" Venus. It's just pixels, pixels, all the way down.

Rob
Venus.jpg
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Re: APOD: Crescent Venus and Moon (2010 May 16)

Post by Ann » Sat May 05, 2012 5:52 pm

Of course the picture isn't phony. Why would it be? Anyone who's got even a small telescope knows that Venus shows phases, and that it has a crescent phase. We all know that the Moon shows phases. There is nothing abnormal whatsoever about the fact that the Moon and Venus can show a crescent phase at the same time. Of course the crescent of the Moon will look much larger from our vantage point than the crescent of Venus, since the Moon is so much closer to us. Obviously, too, the surface brightness of the crescent of Venus will be much higher than the surface brightness of the crescent of the Moon, for the smile reason that Venus is covered by a thick whitish atmosphere, while the surface of the Moon is almost as black as asphalt.

Thanks for showing us the true "pixellation" of this picture, Rob! :D

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Linking blinking stars

Post by neufer » Sun May 06, 2012 6:30 pm

http://astrobob.areavoices.com/?blog=78068 wrote: Venus butts up against the “linking star” tonight
Posted on May 6, 2012 by astrobob

<<If you look to the west at nightfall tonight you’ll notice that Venus has a close companion, the star El Nath. El Nath sits at the tip of Taurus the Bull’s northern horn; its name comes from the Arabic “al nath” meaning “the butting one”. Fitting for a bull, I’d say.

Over the past week or so, Venus and the star have been closing in toward each other. Tonight the two will be closest at only 0.8 degrees apart.

El Nath is also known as Beta Tauri – the second brightest star in Taurus – and shines a bright second magnitude. That hardly compares to Venus’ brilliance. If we could somehow be transported to an imaginary planet orbiting El Nath, we’d be taken aback. Blazing before our eyes would be a star 4.6 times the size of the sun and shining 700 times brighter. Its true brilliance is masked by the 130 light years that separate us. Venus wins out by proximity at a trifling 38 million miles.

El Nath is one of only two “linking stars” in the sky. Linking stars officially belong to one constellation but do double duty filling out the outline of another. El Nath, also called Beta Tauri, completes the familiar pentagonal outline of Auriga the Charioteer directly above Taurus. The other one, Alpheratz (AL-fer-ratz), is Andromeda’s brightest star and completes the well known diamond-shaped Great Square of Pegasus. Without Alpheratz, the Square would collapse into an ordinary triangle.>>
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Re: APOD: Crescent Venus and Moon (2010 May 16)

Post by Beyond » Sun May 06, 2012 6:51 pm

neufer wrote:Without Alpheratz, the Square would collapse into an ordinary triangle.>>
Gee, i'd like to see that!
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Re: APOD: Crescent Venus and Moon (2010 May 16)

Post by neufer » Sun May 06, 2012 7:10 pm

Click to play embedded YouTube video.
.
Beyond wrote:
neufer wrote:
Without Alpheratz, the Square would collapse into an ordinary triangle.>>
Gee, i'd like to see that!
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Re: APOD: Crescent Venus and Moon (2010 May 16)

Post by Beyond » Sun May 06, 2012 8:32 pm

neufer wrote:
Click to play embedded YouTube video.
.
Beyond wrote:
neufer wrote:
Without Alpheratz, the Square would collapse into an ordinary triangle.>>
Gee, i'd like to see that!
I know i'm going to regret asking, but what the hell is THAT about?? :arrow:
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