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APOD: Moon Setting Behind Teide Volcano (2018 Jun 04)
Posted: Mon Jun 04, 2018 4:09 am
by APOD Robot
Moon Setting Behind Teide Volcano
Explanation: These people are not in danger. What is coming down from the left is just the Moon, far in the distance.
Luna appears so large here because she is being
photographed through a telescopic lens. What is moving is mostly
the Earth, whose spin causes
the Moon to slowly disappear behind
Mount Teide, a volcano in the
Canary Islands off the northwest coast of
Africa. The people pictured are
16 kilometers away and many are facing the camera because they are watching
the Sun rise behind the photographer. It is not a
coincidence that a
full moon rises just when the
Sun sets because the Sun is always on the
opposite side of the sky from a full moon. The
featured video was made last week during the full
Milk Moon. The video is not
time-lapse -- this was really how fast the Moon was setting.
Re: APOD: Moon Setting Behind Teide Volcano (2018 Jun 04)
Posted: Mon Jun 04, 2018 4:24 am
by Boomer12k
Great Video... if I had been there I would be "marching" up and down...like I was walking on the Moon...
My Mare Crisium...Moon's Crisium basin... from several nights ago.
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Re: APOD: Moon Setting Behind Teide Volcano (2018 Jun 04)
Posted: Mon Jun 04, 2018 8:36 am
by JohnD
Extraordinary! Of course I know that the Moon (and Sun) move across our sky, but even watching them (Sun-carefully) against a skyline object their speed isn't obvious.
Side issue. When I see a full Moon, I see the Man in the Moon - other cultures see Hares etc. But in telescopic views the paradoeilic image vanishes. Is this cultural, or what?
John
Re: APOD: Moon Setting Behind Teide Volcano (2018 Jun 04)
Posted: Mon Jun 04, 2018 9:36 am
by ygmarchi
There are 1440 minutes in a day. And 720 moon disks or sun disks in a full circle. So on average in takes about 2 minutes for the moon or the sun to set or to rise. Which is more or less how long the movie is.
Re: APOD: Moon Setting Behind Teide Volcano (2018 Jun 04)
Posted: Mon Jun 04, 2018 10:51 am
by Indigo_Sunrise
This is a really great video!
I have a question: in several places, it looks as though there is smoke coming from the top of the mountain. Are the people up there burning bonfire(-type) things? Or is the smoke coming from the volcano itself?
Re: APOD: Moon Setting Behind Teide Volcano (2018 Jun 04)
Posted: Mon Jun 04, 2018 11:44 am
by orin stepanek
Moon went down; All gone!
That is; until tomorrow!
Re: APOD: Moon Setting Behind Teide Volcano (2018 Jun 04)
Posted: Mon Jun 04, 2018 12:58 pm
by bls0326
A really eye-catching video. Good work!
Re: APOD: Moon Setting Behind Teide Volcano (2018 Jun 04)
Posted: Mon Jun 04, 2018 1:24 pm
by neufer
ygmarchi wrote: ↑Mon Jun 04, 2018 9:36 am
There are 1440 minutes in a day. And 720 moon disks or sun disks in a full circle. So on average in takes about 2 minutes for the moon or the sun to set or to rise. Which is more or less how long the movie is.
A Supermoon can take over two and a half minutes to "move" its full width (and longer to set).
Re: APOD: Moon Setting Behind Teide Volcano (2018 Jun 04)
Posted: Mon Jun 04, 2018 1:51 pm
by Chris Peterson
JohnD wrote: ↑Mon Jun 04, 2018 8:36 am
Extraordinary! Of course I know that the Moon (and Sun) move across our sky, but even watching them (Sun-carefully) against a skyline object their speed isn't obvious.
If you've ever tried to set up a non-tracking telescope for other people to view through, you'll know just what a short time you have before having to take it back and reposition it. At very low magnification, as when looking at the entire Moon, you have a minute or two. At higher magnification an object may pass across the entire field in just a few seconds.
Re: APOD: Moon Setting Behind Teide Volcano (2018 Jun 04)
Posted: Mon Jun 04, 2018 3:07 pm
by Rusty Brown in Cda
"...a full moon rises just when the Sun sets because the Sun is always on the opposite side of the sky from a full moon."
I am reminded of Neil Young's lyric from "After the Gold Rush"
I was lying in a burned out basement
With the full moon in my eyes.
I was hoping for replacement
When the sun burst thru the sky.
Great song, but unlikely premise.
Re: APOD: Moon Setting Behind Teide Volcano (2018 Jun 04)
Posted: Mon Jun 04, 2018 3:28 pm
by efahl
Awsome video, can anyone tell me how long that lens is? I see 1.4 + 2.0 extenders, probably on a 1000 mm, so effectively 2800 mm???
Re: APOD: Moon Setting Behind Teide Volcano (2018 Jun 04)
Posted: Mon Jun 04, 2018 6:54 pm
by neufer
Indigo_Sunrise wrote: ↑Mon Jun 04, 2018 10:51 am
I have a question: in several places, it looks as though there is smoke coming from the top of the mountain. Are the people up there burning bonfire(-type) things? Or is the smoke coming from the volcano itself?
https://en.wikipedia.org/wiki/Teide wrote:
.
<<Mount Teide (Spanish: Pico del Teide) is a volcano on Tenerife in the Canary Islands, Spain. Its 3,718-metre summit is the highest point in Spain and the highest point above sea level in the islands of the Atlantic. If measured from the ocean floor, it is at 7,500 m the highest volcano in the world base-to-peak outside of the Hawaiian Islands, and is described by UNESCO and NASA as Earth's third-tallest volcanic structure.
The summit of the volcano has a number of small active fumaroles emitting sulfur dioxide and other gases, including low levels of hydrogen sulfide.>>
Re: APOD: Moon Setting Behind Teide Volcano (2018 Jun 04)
Posted: Mon Jun 04, 2018 7:30 pm
by Biochemiker
efahl wrote: ↑Mon Jun 04, 2018 3:28 pm
Awsome video, can anyone tell me how long that lens is? I see 1.4 + 2.0 extenders, probably on a 1000 mm, so effectively 2800 mm???
Making a lot of assumptions here, but I think twice that? 5600mm focal length? This is a very rough calculation made by measuring the height of a person on the mountain and assuming that he/she is 1.82 meters tall and the distance is 16 km. Then, I assumed that the movie is in the 16x9 format on the Sony APS-C sensor (which would be 6000x4000 on the alpha6300 but cropped to 6000x3375).
Happy to be corrected when someone figures out the actual focal length!
Focal length question
Posted: Mon Jun 04, 2018 7:47 pm
by Biochemiker
The reason that I don't think that my answer is plausible is that the focal length of the telescope necessary for that would be 2000mm (at f/8 it'd have a diameter of 250 mm or 9.8 inches which doesn't look right from the photo). Or, one of the other elements in the path could be an additional 2x teleconverter on a 1000mm focal length telescope. Or, this could be a heavy crop from the full image although this seems unlikely given the image on the tilt-screen.
Re: APOD: Moon Setting Behind Teide Volcano (2018 Jun 04)
Posted: Tue Jun 05, 2018 1:24 am
by Boomer12k
JohnD wrote: ↑Mon Jun 04, 2018 8:36 am
Extraordinary! Of course I know that the Moon (and Sun) move across our sky, but even watching them (Sun-carefully) against a skyline object their speed isn't obvious.
Side issue. When I see a full Moon, I see the Man in the Moon - other cultures see Hares etc. But in telescopic views the paradoeilic image vanishes. Is this cultural, or what?
John
I think that is cultural...now I see....the Energizer Rabbit in The Moon...no really... down near the bottom of the page...see pic...
http://asterisk.apod.com/viewtopic.php? ... it#p253847
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Re: Focal length question
Posted: Mon Jun 11, 2018 2:18 pm
by efahl
Biochemiker wrote: ↑Mon Jun 04, 2018 7:47 pm
Or, this could be a heavy crop from the full image although this seems unlikely given the image on the tilt-screen.
Looking at the framing of the video and the view finder on the camera, I think that the video is indeed is cropped down considerably. The view finder is showing about a 5x-wider chunk of the peak...
Re: Focal length question
Posted: Thu Jun 14, 2018 3:07 pm
by Biochemiker
Ah, yes. You are correct. Maybe not 5x but still a heavy crop.
efahl wrote: ↑Mon Jun 11, 2018 2:18 pm
Biochemiker wrote: ↑Mon Jun 04, 2018 7:47 pm
Or, this could be a heavy crop from the full image although this seems unlikely given the image on the tilt-screen.
Looking at the framing of the video and the view finder on the camera, I think that the video is indeed is cropped down considerably. The view finder is showing about a 5x-wider chunk of the peak...
