Comments and questions about the
APOD on the main view screen.
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APOD Robot
- Otto Posterman
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by APOD Robot » Fri Mar 07, 2014 5:11 am
A View from the Zone
Explanation: Brilliant Venus and the central Milky Way rise in the early morning hours of March 1 in this sea and skyscape. The scene looks out from a beach at Sea Isle City, New Jersey, USA, planet Earth. Of course, Earth orbits well within the solar system's
habitable zone, that
Goldilocks region not too close and not too far from the Sun where surface temperatures can support liquid water.
Similar in size to Earth,
Venus lies just beyond the inner boundary of the habitable zone. The watery
reflection of light from our inhospitable
sister planet is seen along a calm, cold ocean and low cloud bank.
[/b]
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Boomer12k
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by Boomer12k » Fri Mar 07, 2014 5:22 am
It is so important...it is UNDERLINED!!!
What a great shot.
And there is glow on the water below the clouds too...it is really amazing that Venus is so bright, the camera can capture reflections of it.
I thought it was The Moon at first.
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Ann
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by Ann » Fri Mar 07, 2014 6:38 am
Lovely picture. Yes, that really could have been the Moon. Of course, a full Moon would have overwhelmed the light from the Milky Way.
Ann
Color Commentator
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epsztein
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by epsztein » Fri Mar 07, 2014 7:21 am
Ann, the answer is in your question: if you see the Milky so well, the bright one has to be Venus; as what we ignore is the angle of aperture of the picture, while time of exposure can be guessed by the receeding waters, and funny enough, an imperfection in APOD comments that can be spotted: a very rare observation, in this part of the galaxy at least: it is not a "low cloud" below Venus, but a high one... not that it is important, but since we all do love our guides...
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Paressa
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by Paressa » Fri Mar 07, 2014 8:10 am
Wonderful picture! I do not have a clear view of the east where I reside and these views are always welcome.
epsztein wrote:.... it is not a "low cloud" below Venus, but a high one... not that it is important, but since we all do love our guides...
There are actually two
underlining clouds. One that is high just below Venus, and the other is the one that cuts Venus' reflection in two. That originally looked to me like a bright band in the water, perhaps created by Noctiluca scintillans, but after close inspection it is a "low cloud bank".
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epsztein
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by epsztein » Fri Mar 07, 2014 9:07 am
To Parnessa: I respectfully disagree: the "cloud" that cuts Venus in two is simply a sea wave that is also not totally clear, as it did have some time to move. Furthermore there are lights of at leat two ships, possibly three, visible on either side on Venus and they are behind the horizon, unless there is some island out there.
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CURRAHEE CHRIS
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by CURRAHEE CHRIS » Fri Mar 07, 2014 1:39 pm
Beautiful shot!!! It is nice for me to see something relatively close to where I live. (Pennsylvania). I always feel like the horrible cloud cover blocks most decent shots here in Pa. It seems like I need to move out west (which im going to do when I retire
) or live on the other side of the planet. Kudos to the photographer from Jersey!!!
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retrogalax
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by retrogalax » Fri Mar 07, 2014 2:41 pm
Very artistic , i like how the orange nuances of the sky and the sea shore are playing together in an subtle monochromatic effect.
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Psnarf
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by Psnarf » Fri Mar 07, 2014 3:00 pm
Thanks to reading APODs, I can now point out a couple of globular clusters right of center.
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Ann
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by Ann » Fri Mar 07, 2014 3:16 pm
Psnarf wrote:Thanks to reading APODs, I can now point out a couple of globular clusters right of center.
I think you are referring to
open clusters M7 and M6.
There really are several globular clusters in this part of the sky, but they are too distant and therefore too faint to really show up in this kind of picture.
Ann
Color Commentator
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orin stepanek
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by orin stepanek » Fri Mar 07, 2014 3:30 pm
Orin
Smile today; tomorrow's another day!
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Chris Peterson
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by Chris Peterson » Fri Mar 07, 2014 3:31 pm
Ann wrote:I think you are referring to
open clusters M7 and M6.
There really are several globular clusters in this part of the sky, but they are too distant and therefore too faint to really show up in this kind of picture.
Actually, they are plenty bright. It's just that at this image scale, they appear very nearly stellar.
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neufer
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by neufer » Fri Mar 07, 2014 4:10 pm
http://en.wikipedia.org/wiki/Sea_Isle_City,_New_Jersey wrote:
<<Sea Isle City's signature water tower always had "Welcome to Sea Isle City" painted on it until 2002 when the printed message was changed to "Smile! You're in Sea Isle City". "Sara the Turtle Day" is the city's local holiday, celebrating a fictional turtle named Sara who became the city's unofficial mascot. Sea Isle City became one of the first towns in New Jersey to receive LED streetlights powered solely by wind and solar energy.>>
Last edited by neufer on Fri Mar 07, 2014 6:42 pm, edited 1 time in total.
Art Neuendorffer
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Ann
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by Ann » Fri Mar 07, 2014 4:39 pm
Orin, I can see that you have 4151 posts right now! That reminds me of the interesting Seyfert galaxy
NGC 4151!
The fact that NGC 4151 is a Seyfert galaxy means that it has an active black hole at its center.
Ann
Color Commentator
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neufer
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by neufer » Fri Mar 07, 2014 5:09 pm
Ann wrote:
Orin, I can see that you have 4151 posts right now!
That reminds me of the interesting Seyfert galaxy
NGC 4151
[which] has an active black hole at its center.
- I, too, have always had my suspicions about Orin.
Art Neuendorffer
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Ron-Astro Pharmacist
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by Ron-Astro Pharmacist » Fri Mar 07, 2014 7:07 pm
Is Venus trying to tell us it will have the last word (or letter)?
It looks like an Omega Ω. Is that a cloud forming the underline? Even from behind the low cloud bank - it's showing off. Why doesn't it appear more crescent-like?
Make Mars not Wars
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Anthony Barreiro
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by Anthony Barreiro » Fri Mar 07, 2014 7:08 pm
CURRAHEE CHRIS wrote:Beautiful shot!!! It is nice for me to see something relatively close to where I live. (Pennsylvania). I always feel like the horrible cloud cover blocks most decent shots here in Pa. It seems like I need to move out west (which im going to do when I retire
) or live on the other side of the planet. Kudos to the photographer from Jersey!!!
At first I thought you were referring to Venus as relatively nearby, not New Jersey! It's all relative.
May all beings be happy, peaceful, and free.
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SamS
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by SamS » Fri Mar 07, 2014 8:10 pm
There's a streak in the top left corner. Satellite or meteor?
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neufer
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by neufer » Fri Mar 07, 2014 8:52 pm
Ron-Astro Pharmacist wrote:
Is Venus trying to tell us it will have the last word (or letter)?
It looks like an Omega Ω. Is that a cloud forming the underline?
Ron-Astro Pharmacist wrote:
Even from behind the low cloud bank - it's showing off. Why doesn't it appear more crescent-like?
Each point star becomes a tiny Airy disk diffraction pattern.
Each overexposed star becomes a saturated Airy disk diffraction pattern(; i.e., a bright circle surrounded by narrow rings).
Venus becomes a fat
highly saturated Airy disk diffraction pattern
convoluted with a tiny crescent(; i.e., basically just a very large bright circle).
http://en.wikipedia.org/wiki/Airy_disk wrote:
<<In optics, the Airy disk (or Airy disc) and Airy pattern are descriptions of the best focused spot of light that a perfect lens with a circular aperture can make, limited by the diffraction of light.>>
Art Neuendorffer
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Chris Peterson
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by Chris Peterson » Fri Mar 07, 2014 9:48 pm
neufer wrote:Each overexposed star becomes a saturated Airy disk diffraction pattern(; i.e., a bright circle surrounded by narrow rings).
Venus becomes a fat
highly saturated Airy disk diffraction pattern
convoluted with a tiny crescent(; i.e., basically just a very large bright circle).
Sounds good in theory, but that's not really what we're seeing.
The image scale is 3.3 arcmin/pixel. At f/4 (just guessing) the Airy disk will be about the size of a single pixel on the camera sensor (5 um). The image of Venus is saturated to about 10 pixels diameter, or a bit larger than the full Moon. Even allowing for the smearing of the Airy disk due to the fact that his is white light, there's no way that what we're seeing is primarily a diffraction effect. Venus is bloated by scatter and internal reflections from the optics.
Optically, Venus occupies less than 1/6 of a single pixel, so even with perfect optics and no diffraction it would never appear more than a point source, with no structure.
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orin stepanek
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by orin stepanek » Fri Mar 07, 2014 10:00 pm
neufer wrote:Ann wrote:
Orin, I can see that you have 4151 posts right now!
That reminds me of the interesting Seyfert galaxy
NGC 4151
[which] has an active black hole at its center.
- I, too, have always had my suspicions about Orin.
Oh Ann; now I messed it up! I added a couple of posts!
Art: How much do you know?
Orin
Smile today; tomorrow's another day!
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Ron-Astro Pharmacist
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by Ron-Astro Pharmacist » Fri Mar 07, 2014 11:16 pm
Chris Peterson wrote:neufer wrote:Each overexposed star becomes a saturated Airy disk diffraction pattern(; i.e., a bright circle surrounded by narrow rings).
Venus becomes a fat
highly saturated Airy disk diffraction pattern
convoluted with a tiny crescent(; i.e., basically just a very large bright circle).
Sounds good in theory, but that's not really what we're seeing.
The image scale is 3.3 arcmin/pixel. At f/4 (just guessing) the Airy disk will be about the size of a single pixel on the camera sensor (5 um). The image of Venus is saturated to about 10 pixels diameter, or a bit larger than the full Moon. Even allowing for the smearing of the Airy disk due to the fact that his is white light, there's no way that what we're seeing is primarily a diffraction effect. Venus is bloated by scatter and internal reflections from the optics.
Optically, Venus occupies less than 1/6 of a single pixel, so even with perfect optics and no diffraction it would never appear more than a point source, with no structure.
I've noticed the opposite can be true here on Earth. Light reflecting from my head does not indicate a h'airy' disc.
Today's photo shows much more favorable and interesting reflections.
Back to the light point question considering your responses, for collimating my reflector, do you think one light source better than another? (Not that I would likely choose Venus but it is a nice bright object)
Thanks, Art & Chris
Make Mars not Wars
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Anthony Barreiro
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by Anthony Barreiro » Fri Mar 07, 2014 11:35 pm
Ron-Astro Pharmacist wrote:...Back to the light point question considering your responses, for collimating my reflector, do you think one light source better than another? (Not that I would likely choose Venus but it is a nice bright object)
You should collimate a telescope at the highest magnification atmospheric conditions allow. At high magnification planets are not point sources, they're disks, or crescent or gibbous. It's best to pick a star that's bright but not so bright that it's scintillating a lot. Stars that are higher in the sky will be steadier because you're looking through less atmosphere. If you're using a tracking mount, any star will do. If your mount doesn't track, Polaris is the best collimation star (in the northern hemisphere), because it's relatively bright and it's the slowest moving star in the sky.
May all beings be happy, peaceful, and free.
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Chris Peterson
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by Chris Peterson » Fri Mar 07, 2014 11:36 pm
Ron-Astro Pharmacist wrote:Back to the light point question considering your responses, for collimating my reflector, do you think one light source better than another? (Not that I would likely choose Venus but it is a nice bright object)
Collimation is best performed at high magnification, and through even a small aperture, Venus is not an optical point source. Use a bright star for collimation, high in the sky to minimize atmospheric effects. If you don't have a tracking mount, Polaris is pretty good if it's reasonably high for you.
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Dick Shun'ry
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by Dick Shun'ry » Sat Mar 08, 2014 12:41 am
"Habitability is the conformance of a residence or abode to the implied warranty of habitability. A residence that complies is said to be "habitable". It is an implied warranty or contract, meaning it does not have to be an express contract, covenant, or provision of a contract. It is a common law right of a tenant or legal doctrine.[1]
In order to be habitable, such housing usually:
must provide shelter, with working locks
must be heated in the winter months (typically between October 1 and May 31 in the Northeastern United States)[2]
must not be infested with vermin, such as mice, roaches, termites, mold,[3] etc.
requires the landlord to stop other tenants from making too much noise (as measured by the decibel scale), second-hand smoke,[4] or from selling narcotics
must provide potable water"
I guess earth is not habitable.