Atlantis and Hubble (viewed from earth)

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Discussion Overview

The discussion revolves around the images of the Space Shuttle Atlantis as it transits in front of the Sun, as well as questions about the authenticity of photographs of the Milky Way galaxy. Participants explore the technical aspects of capturing such images and the nature of astronomical photography.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants inquire about the method of capturing images of Atlantis in front of the Sun, questioning the apparent size of the shuttle relative to the Sun.
  • One participant explains that the Shuttle appears small due to its altitude, comparing it to an airplane at a lower altitude.
  • Another participant provides details about the telescope and camera settings used to take the images, emphasizing the importance of magnification and distance.
  • Questions arise regarding the authenticity of images of the Milky Way, with some participants asserting that such images are not direct photographs but rather artistic representations.
  • Some participants discuss the challenges of photographing the entire Milky Way due to dust obscuring the view from within the galaxy.
  • There is mention of the number of galaxies in the observable universe and the ability to see out of the Milky Way, depending on the direction of observation.
  • One participant suggests that while we cannot take a picture of the entire Milky Way, we can estimate its shape based on star counts in various directions.

Areas of Agreement / Disagreement

Participants express differing views on the nature of images of the Milky Way, with some asserting they are real photographs while others argue they are artistic conceptions. The discussion remains unresolved regarding the authenticity of specific images and the methods of capturing them.

Contextual Notes

There are limitations regarding the assumptions made about the size and distance of celestial objects, as well as the definitions of what constitutes a "real" photograph in astronomical contexts.

Who May Find This Useful

Individuals interested in astronomy, astrophotography, and the nature of celestial imagery may find this discussion insightful.

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gizmodo.com/5255723/amateur-astronomer-captures-stunning-images-of-atlantis-hubble-in-the-face-of-the-sun

hubbletop.jpg


The source of the images is at
www.astrosurf.com/legault/atlantis_hst_transit.html
(but the site might be slow now). (Similar but older photos at http://legault.club.fr/iss_atlantis_transit.html )
direct link: www.astrosurf.com/legault/atlantis_hst_2009may13_50.jpg

sun.jpg
 
Last edited by a moderator:
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Wow !
 
:cool:
 
How are these pictures taken? The sun isn't that big when viewed from the earth...? If you're focusing on the sun wouldn't the shuttle look huge? can someone explain this?
 
Dear god, they are heading RIGHT FOR THE SUN!
 
Cyrus said:
Dear god, they are heading RIGHT FOR THE SUN!

Well! don't just set there, grab the wheel.:smile:
 
CINA said:
How are these pictures taken? The sun isn't that big when viewed from the earth...? If you're focusing on the sun wouldn't the shuttle look huge? can someone explain this?

Did you follow the link in my post?
It says
"Shot just after launch, the image shows the faraway scene as viewed through a Takahashi TOA-130 refractor telescope (focal length 2200mm) and a Baader solar prism, which gives the Sun its muted look. Strapped to the back of the telescope, the 5D was set to ISO 100 and a 1/8000 shutter speed, the camera's extreme low and high settings, respectively [Edit: woops, the Mk II actually does ISO 50]."
 
robphy, the question was about magnification, not brightness.
CINA said:
How are these pictures taken? The sun isn't that big when viewed from the earth...? If you're focusing on the sun wouldn't the shuttle look huge? can someone explain this?
With a normal telescope, the Space Shuttle looks tiny - it is at an altitude of more than 500 km when servicing the hubble. Consider how an airplane looks at an altitude of 10 km - recognizable as an airplane, but only barely. The shuttle is only a few arcseconds across at that altitude, while the sun is 30 arcminutes (1800 arcseconds) across. Yes, the sun really does appear that much bigger than the space shuttle in orbit.
 
CINA said:
How are these pictures taken? The sun isn't that big when viewed from the earth...? If you're focusing on the sun wouldn't the shuttle look huge? can someone explain this?
The Shuttle and Hubble Space Telescope are at an altitude of approximately 350 miles (563 km), and the sun is about 93 million miles (149 million km) from the earth, and the sun has a diameter of 870,000 miles (1.4 million km). The Shuttle orbiter is only 122 ft (37 m) nose to tail.

http://www.space.com/missionlaunches/090515-sts125-sts125-solar-transit.html
 
  • #10
CINA said:
How are these pictures taken? The sun isn't that big when viewed from the earth...? If you're focusing on the sun wouldn't the shuttle look huge? can someone explain this?

https://www.youtube.com/watch?v=98hO97ky-sA
 
  • #11
that pop up a question, you know the different photos of the galaxies like the milky way filled with billions of stars, are they real photos? If so how can such photos be taken, isn’t our solar system part of the milky way :confused:
 
  • #12
Great post!
 
  • #13
drizzle said:
photo of the milky way
I'd love to see that one.
 
  • #14
drizzle said:
that pop up a question, you know the different photos of the galaxies like the milky way filled with billions of stars, are they real photos? If so how can such photos be taken, isn’t our solar system part of the milky way :confused:
Confused is right! The way you worded that doesn't make any sense in the context of the question. Photos of galaxies like the milky way are not photos of the milky way. There are hundreds of galaxies that are readily accessible to amateur astronomers and millions of them detectable by professionals.
 
  • #15
drizzle said:
that pop up a question, you know the different photos of the galaxies like the milky way filled with billions of stars, are they real photos?
Yes

If so how can such photos be taken, isn’t our solar system part of the milky way :confused:
Whats the problem?
 
  • #16
humanino said:
I'd love to see that one.
It is bad form to cut up/rearrange a quote, but in any case, here's one that meets your request: http://www.astropix.com/HTML/D_SUM_S/MILKYWAY.HTM
 
  • #17
russ_watters said:
It is bad form to cut up/rearrange a quote, but in any case, here's one: http://www.astropix.com/HTML/D_SUM_S/MILKYWAY.HTM
I'd send a photo of myself from the inside... but I don't want to be banned.
 
  • #18
More seriously though, is it not possible to reconstruct the image of the Milky Way as seen from outside ? We have enough data.
 
  • #19
humanino said:
More seriously though, is it not possible to reconstruct the image of the Milky Way as seen from outside ? We have enough data.
Not really, since the disk obscures the disk. But here are some estimations: http://cass.ucsd.edu/public/tutorial/MW.html
From the site:
Since the Earth lies in the disk of the Milky Way, dust prevents us from determining the large scale structure of the Galaxy's spiral pattern beyond a few thousand light-years. Radio observations have detailed the structure of the gas in the spiral arms, but it is still not known if our galaxy is a normal spiral like our neighbor Andromeda, or a barred spiral like shown to the left. The bulge of the galaxy is slightly elongated in the direction of the Sun, which may be due to a bar.
 
  • #20
russ_watters said:
Confused is right! The way you worded that doesn't make any sense in the context of the question. Photos of galaxies like the milky way are not photos of the milky way. There are hundreds of galaxies that are readily accessible to amateur astronomers and millions of them detectable by professionals.

I see, it's hard to get it. will, like = i.e. = for example, and I know there are hundreds of other galaxies other than the milky way

mgb_phys said:
Whats the problem?

the pro is how can this photo be taken?
 
  • #21
There are lots of other galaxies (about 1011 in the observable universe)
The milky way is a fairly typical spiral galaxy, there are a lot of nearby spiral galaxies.
We can see out of our own galaxy fairly easily unless we look toward the centre, because the stars are a long way apart.
If you look toward the centre of the galaxy you see a lot more stars as in this photo http://www.astropix.com/HTML/D_SUM_S/MILKYWAY.HTM
It's a bit like being in the suburbs of a city, if you look towar downtown you see a lot of lights but if you look outward you see less.

We can't take a picture of the whole of our own galaxy but we can work out it's shape by counting the number of stars in each direction around us and then working out what it would look like from outside ( it's the same sort of calcuation you do for a CAT scan)
 
  • #22
mgb_phys said:
We can't take a picture of the whole of our own galaxy but we can work out it's shape by counting the number of stars in each direction around us and then working out what it would look like from outside ( it's the same sort of calcuation you do for a CAT scan)

great, so those pictures of the milky way are not REAL photos, right?
 
  • #23
Ok I understand your question now!
The picture of the centre of the galaxy in the above link is genuine, photos of other spiral galaxies are real but photos of the whole of our galaxy aren't
 
  • #24
drizzle said:
great, so those pictures of the milky way are not REAL photos, right?

What pictures of the Milky Way? Link please?

Yes, if it claims to be the Milky Way it is an "artists conception".
 
  • #25
Integral said:
What pictures of the Milky Way? Link please?

Yes, if it claims to be the Milky Way it is an "artists conception".

See the links posted earlier in this thread by russ_watters
 
  • #26
Great thread!

I think this may have sparked me to read more about Astronomy and Physics.

Looking up at the sky and wondering is all it takes. Maybe even buying a telescope.
 
  • #27
Integral said:
What pictures of the Milky Way? Link please?

Yes, if it claims to be the Milky Way it is an "artists conception".
Drizzle said:
See the links posted earlier in this thread by russ_watters
No! Please, guys, we need precision of wording here. I posted a link to a picture - a photo - of the Milky Way that is quite real. Here is the exposure data:
Exposure Data

Lens: Nikkor 16mm f/2.8 full frame fisheye
F/stop: 2.8
Exposure: 15 minutes
Film: Hypersensitized Fujichrome 100 RDP
Filter: None
Exposure start: 3:45 am
Date: April 10, 1986
Location: An observing site at 10,000 feet near Puquina, Peru
Notes: Sagittarius and Scorpius nearly overhead!
This photo does not purport to be of the entire galaxy, but only of the part of the galaxy we can see. Please remember: the reason our galaxy is called "The Milky Way Galaxy" is because of how it looks from earth!

I also posted a link to a site that contains (among other things) reconstructions of what the entire galaxy might look like. These are simulations, not photos.

This issue really is simple if you are explicit:

-If an image shows the entire Milky Way Galaxy, it can only be a simulation/artists rendering.
-If an image is of just the part visible from Earth (aka "The Milky Way"), then it may be/probably is a real photo.
-Other galaxies can be photographed in their entirety because we aren't in them.
 
  • #28
russ_watters said:
This issue really is simple if you are explicit:

-If an image shows the entire Milky Way Galaxy, it can only be a simulation/artists rendering.
-If an image is of just the part visible from Earth (aka "The Milky Way"), then it may be/probably is a real photo.
-Other galaxies can be photographed in their entirety because we aren't in them.



and the bottom line of this is that there’s no real photo of the Milky Way and will never be [of the entire galaxy] :approve:
 
  • #29
drizzle said:
and the bottom line of this is that there’s no real photo of the Milky Way and will never be [of the entire galaxy] :approve:
Of the whole galaxy no.
Photos of the milky way are pictures of the central core of our galaxy, called the 'milky way' because on a clear-dark site it does look like a white milky cloud.
 
  • #30
drizzle said:
there’s no real photo of the Milky Way and will never be [of the entire galaxy] :approve:

Never? What about those thaken by M31 inhabitants?
 

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