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APOD: Orion over Green Bank (2022 Feb 23)
Posted: Wed Feb 23, 2022 5:05 am
by APOD Robot
Orion over Green Bank
Explanation: What will the huge Green Bank Telescope discover tonight? Pictured, the
Robert C. Byrd Green Bank Telescope (GBT) on the lower right is the largest fully-pointable single-dish
radio telescope in the world. With a central dish larger than a football field, the
GBT is nestled in the hills of
West Virginia,
USA in a
radio quiet zone where the use of cell phones, WiFi emitters, and even microwave ovens are limited. The
GBT explores our universe not only during the night -- but during the day, too, since the daytime sky is typically dark in
radio waves. Taken in late January, the featured image was planned for months to get the setting
location of
Orion just right. The image is a composite of a foreground shot taken over a kilometer away from the
GBT, and a background shot built up of long exposures during the previous night. The deep background image of
Orion is
fitting because the GBT is famous for, among
many discoveries, mapping the
unusual magnetic field in the
Orion Molecular Cloud Complex.
Re: APOD: Orion over Green Bank (2022 Feb 23)
Posted: Wed Feb 23, 2022 11:26 am
by Dan
Way too many "composites" these days...
Re: APOD: Orion over Green Bank (2022 Feb 23)
Posted: Wed Feb 23, 2022 12:53 pm
by orin stepanek
For some reason, the blue color seems so unreal to me;
but maybe it's just my perception!
It would be nice if their SETI work gives dividends.
This is so embarrassing; I can't get my paws out!
What a cute kitty! 🥰
Re: APOD: Orion over Green Bank (2022 Feb 23)
Posted: Wed Feb 23, 2022 1:28 pm
by N2LO
IS..
The GBT explores our universe not only during the night -- but during the day, too, since the daytime sky is typically dark in radio waves.
Should Be..
The GBT explores our universe not only during the night -- but during the day, too, since the daytime sky is ALSO BRIGHT in radio waves.
N2LO@comcast.net
Re: APOD: Orion over Green Bank (2022 Feb 23)
Posted: Wed Feb 23, 2022 1:55 pm
by Eric
Dan wrote: ↑Wed Feb 23, 2022 11:26 am
Way too many "composites" these days...
Agree.
Re: APOD: Orion over Green Bank (2022 Feb 23)
Posted: Wed Feb 23, 2022 1:59 pm
by Eric
N2LO wrote: ↑Wed Feb 23, 2022 1:28 pm
IS..
The GBT explores our universe not only during the night -- but during the day, too, since the daytime sky is typically dark in radio waves.
Should Be..
The GBT explores our universe not only during the night -- but during the day, too, since the daytime sky is ALSO BRIGHT in radio waves.
N2LO@comcast.net
Yes. Also: "the use of cell phones...IS limited", not "ARE limited".
Re: APOD: Orion over Green Bank (2022 Feb 23)
Posted: Wed Feb 23, 2022 2:02 pm
by Chris Peterson
Dan wrote: ↑Wed Feb 23, 2022 11:26 am
Way too many "composites" these days...
Virtually every image is a "composite".
Re: APOD: Orion over Green Bank (2022 Feb 23)
Posted: Wed Feb 23, 2022 5:16 pm
by dennis.mabrey
I am always amazed at how many things in WV are named after Robert C. Byrd... The king of pork spending.
Re: APOD: Orion over Green Bank (2022 Feb 23)
Posted: Wed Feb 23, 2022 10:06 pm
by johnnydeep
Eric wrote: ↑Wed Feb 23, 2022 1:59 pm
N2LO wrote: ↑Wed Feb 23, 2022 1:28 pm
IS..
The GBT explores our universe not only during the night -- but during the day, too, since the daytime sky is typically dark in radio waves.
Should Be..
The GBT explores our universe not only during the night -- but during the day, too, since the daytime sky is ALSO BRIGHT in radio waves.
N2LO@comcast.net
Yes. Also: "the use of cell phones...IS limited", not "ARE limited".
Actually, regarding the 'dark' versus 'light' distinction, no. I believe the original text is correct. The daytime sky is bright in optical light, hence it's not a suitable time for optical telescopic observations. In contrast, the night time sky is dark in visible light, meaning that visible light sources outside the atmosphere can shine through.
Similarly, the daytime sky is dark in radio waves since radio sources outside the atmosphere can get through, just as with the night time sky.
Re: APOD: Orion over Green Bank (2022 Feb 23)
Posted: Thu Feb 24, 2022 1:02 am
by DonB312
I see some posts saying the image is a fake. However, I am having trouble seeing anything fake about it. The foreground appears to have been accurately placed over the background. The objects in the foreground (building, telescope, forest, etc.) are actually there. The sky image is showing what is actually there. Granted, if we stood there and looked at this scene with our own eyes we wouldn't see all that we see in this photo. But I think of that as a case where the photo shows more of reality than our own eyes show us. I am so glad we have technology and techniques (including compositing) and people skilled at using them to show us much more of the real universe than we can otherwise perceive.
Re: APOD: Orion over Green Bank (2022 Feb 23)
Posted: Thu Feb 24, 2022 1:22 pm
by johnnydeep
DonB312 wrote: ↑Thu Feb 24, 2022 1:02 am
I see some posts saying the image is a fake. However, I am having trouble seeing anything fake about it. The foreground appears to have been accurately placed over the background. The objects in the foreground (building, telescope, forest, etc.) are actually there. The sky image is showing what is actually there. Granted, if we stood there and looked at this scene with our own eyes we wouldn't see all that we see in this photo. But I think of that as a case where the photo shows more of reality than our own eyes show us. I am so glad we have technology and techniques (including compositing) and people skilled at using them to show us much more of the real universe than we can otherwise perceive.
Well said!