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The astronomical news community would do the public a very big favor if they started stating clearly which pictures are taken by telescopes and which are cgi.

ifdefdebug 7y ago
Yes, I have meat people who thought pictures of our galaxy were actually pictures of our galaxy. (edit: I mean, from outside)
- DavidHm 7y ago
  See, I wasn't sure whether that's a typo or the way an AI would refer to us.
  - EvanAnderson 7y ago
    They're made out of meat: https://www.mit.edu/people/dpolicar/writing/prose/text/thinkingMeat.html https://www.mit.edu/people/dpolicar/writing/prose/text/think...
- gus_massa 7y ago
  When I was young the Milky way "was" an spiral galaxy, now it "is" a barred spiral galaxy and the "photo" changed according. :)
  - raattgift 7y ago
    Think of what it "was" when your grandparents were young! In the 1910s, the observables were extremely faint visible-light nebulae, with M13 (Hercules) closely comparable to M33 (Triangulum), although the spiral structure and larger solid angle of the latter was known since 1850: http://www.messier.seds.org/more/m033_rosse.html http://www.messier.seds.org/more/m033_rosse.html (This only about five years after the first known resolution of nebulae into elliptical, spiral, and irregular; at the time the linked sketch was drawn there were enough observations of spiral nebulae to decide that M33 must be one as well). Observations were consistent with an extragalactic but nearby star cluster. Better observations led to an evolution of what, retrospectively, M33 "was": from closely comparable with M13 to more than a hundred times further away (~ 6.8 vs ~ 850kpc), and tens of billions rather than hundreds of thousands of stars. Perhaps it's best to think of "was" and "is" in relation to human observations. (This also comes up whenever someone objects to talking in the present sense about today's observations of objects at kiloparsec distances, as in "Sag A* is noisy today" provoking "no, it was noisy 26 000 years ago!" -- and of course hypotheses about what exactly generates the Sag A* observables have not fossilized yet). There are still large uncertainties about the exact structure of our own galaxy, but the (cosmological) Copernican principle is alive and well in that area of galactic astronomy since galaxy zoos are full of various subtypes of dusty spirals.
    - gus_massa 7y ago
      I remember from the original serie Cosmo that the Milky way "had" no bars. I found it http://www.youtube.com/watch?v=1-OdJmAefOY&t=13m51s http://www.youtube.com/watch?v=1-OdJmAefOY&t=13m51s I was very surprised to know the "change" a few years ago. I understand that they were using the best models available at that time, and with better equipment it was posible to get a better model so the image got outdated.
paulstovell 7y ago
This. I find it all confusing. Article A: Here’s a photo of a another galaxy so far away, showing XYZ. Article B: We suspect there’s another planet in our own solar system but we can’t find it and supposedly it’s too far away for us to photograph it.
- SiempreViernes 7y ago
  Surely there is nothing too strange about this? A light house can be seen from very far away, but you need not drop your keys very far away in a parking lot before they become impossible to find.
- caf 7y ago
  Several galaxies have angular diameters when viewed from Earth of more than 1 degree. The Large Magellanic Cloud is 11 degrees! None of the planets in our solar system are anywhere near this big in the sky - the Moon is only half a degree. Getting a brighter picture of something that's dim just requires collecting more light - essentially taking a longer exposure. But getting a sharper picture of something that's very small in the sky is limited by both the aperture of the telescope (the diffraction limit) and the atmospheric distortion, if you're viewing from the ground.
jcims 7y ago
That and including a standard scale for apparent width. I always thought that photos of other galaxies resolved into specks the size of stars in the night sky. This composite of Andromeda and the moon blew my mind: https://apod.nasa.gov/apod/ap061228.html https://apod.nasa.gov/apod/ap061228.html
- TeMPOraL 7y ago
  Holy hell, thank you for that! I was under the same impression as well. The photo just made me appreciate how big the galaxies are!
- sandworm101 7y ago
  But that isnt what you would see by eye or even a normal telescope. That is a long-exposure image. By eye you can only see the brighter/smaller core. Get a more sensitive camera, something able to see the diffuse gas and dimmer stars, and andromeda would be twice even that size.
  - Fernicia 7y ago
    I don't think anyone is under the impression that image can be seen with the naked eye.
    - jcims 7y ago
      You're right! But I tried tonight just to see if it was possible to see anything at all. My eyes are kind of shitty but we live out in the boonies with no light pollution. There's a little 'yellow brick road' of stars that lead you to it and if i looked slightly aside i could juuuuuuuuust make out the slightest smudge where it is supposed to be. It was right on the edge of my ability to perceive it, need to try again after spending an hour in the dark.
  - misterprime 7y ago
    I think the goal is to get a better sense of "how much of my visual space would this object occupy if I could see it". I had no idea Andromeda would appear larger than the moon from here if I could see it with my naked eyes. That really helps me get a sense of the size. "Wow, it's that large even though it's that far away!?"
caymanjim 7y ago
> The astronomical news community would do the public a very big favor if they started stating clearly which pictures are taken by telescopes and which are cgi. I agree that there ought to be clearer indications of which images come from sensor data and which are purely simulated, but all sensor images are heavily processed. I worked on Mars Global Surveyor, Mars Odyssey, MRO, LRO, and other NASA missions, and wrote image processing software for various instruments on those spacecraft (primarily infrared cameras). They're not simply snapshots like you'll get from your DSLR. Even the most DSLR-like cameras tend to image in many spectral bands (e.g. 11 bands ranging from infrared through visual into UV). An image you see in a magazine typically selects three spectral bands and assigns them to red, green, and blue. Almost none of the images you see are true color, in part because almost none of the instruments have 3-band RGB sensors like you might see in your DSLR. There are many reasons for this, but the two biggest ones are that much of the universe is opaque to visual frequencies (you need infrared or other sensors to penetrate clouds of dust), and much of the scientifically interesting data isn't present in the visual spectrum (infrared is used to determine mineral composition, like finding hematite on Mars, which is evidence of water in the past). Images of the surface of planets comes from a complex stitching-together of long, thin strips of data (again in many non-visual frequencies), which are taken from different angles, at different times of day. In order to create the uniform, visually-appealing (and also scientifically-valuable) images of the surface of Mars that you see, the images are heavily processed to balance albedo and adjust other anomalies. One little-known fact is that gravitationally, none of the large, rocky celestial bodies are spherical; the moon in particular is a very lumpy potato shape. This means that an orbit around the moon is nowhere near a perfect ellipse; it wobbles up and down all the time, which means the distance of the camera from the surface changes all the time. All of this has to be compensated for. During processing, everything is stretched to align, and hundreds/thousands of images of the same region from different times (over many years) are averaged together to get the final product. All of this is a long way of saying that literally every astronomical image you've seen is computer-generated and heavily processed. There's value in knowing which images started with sensor data and which are pure simulation, but there's no value in non-computer-generated imagery. It's hard to explain this quickly in an image caption. We used to have to deal with conspiracy quacks all the time, demanding that we release the "real images" rather than our "manipulated images" so that they could find the aliens on Mars, but the simple truth is that there are no "real images". It's all sensor data in a form that is completely useless without extensive processing.

ifdefdebug 7y ago

Yes, I have meat people who thought pictures of our galaxy were actually pictures of our galaxy. (edit: I mean, from outside)

DavidHm 7y ago
See, I wasn't sure whether that's a typo or the way an AI would refer to us.
- EvanAnderson 7y ago
  They're made out of meat: https://www.mit.edu/people/dpolicar/writing/prose/text/thinkingMeat.html https://www.mit.edu/people/dpolicar/writing/prose/text/think...
gus_massa 7y ago
When I was young the Milky way "was" an spiral galaxy, now it "is" a barred spiral galaxy and the "photo" changed according. :)
- raattgift 7y ago
  Think of what it "was" when your grandparents were young! In the 1910s, the observables were extremely faint visible-light nebulae, with M13 (Hercules) closely comparable to M33 (Triangulum), although the spiral structure and larger solid angle of the latter was known since 1850: http://www.messier.seds.org/more/m033_rosse.html http://www.messier.seds.org/more/m033_rosse.html (This only about five years after the first known resolution of nebulae into elliptical, spiral, and irregular; at the time the linked sketch was drawn there were enough observations of spiral nebulae to decide that M33 must be one as well). Observations were consistent with an extragalactic but nearby star cluster. Better observations led to an evolution of what, retrospectively, M33 "was": from closely comparable with M13 to more than a hundred times further away (~ 6.8 vs ~ 850kpc), and tens of billions rather than hundreds of thousands of stars. Perhaps it's best to think of "was" and "is" in relation to human observations. (This also comes up whenever someone objects to talking in the present sense about today's observations of objects at kiloparsec distances, as in "Sag A* is noisy today" provoking "no, it was noisy 26 000 years ago!" -- and of course hypotheses about what exactly generates the Sag A* observables have not fossilized yet). There are still large uncertainties about the exact structure of our own galaxy, but the (cosmological) Copernican principle is alive and well in that area of galactic astronomy since galaxy zoos are full of various subtypes of dusty spirals.
  - gus_massa 7y ago
    I remember from the original serie Cosmo that the Milky way "had" no bars. I found it http://www.youtube.com/watch?v=1-OdJmAefOY&t=13m51s http://www.youtube.com/watch?v=1-OdJmAefOY&t=13m51s I was very surprised to know the "change" a few years ago. I understand that they were using the best models available at that time, and with better equipment it was posible to get a better model so the image got outdated.

paulstovell 7y ago

This. I find it all confusing. Article A: Here’s a photo of a another galaxy so far away, showing XYZ. Article B: We suspect there’s another planet in our own solar system but we can’t find it and supposedly it’s too far away for us to photograph it.

SiempreViernes 7y ago
Surely there is nothing too strange about this? A light house can be seen from very far away, but you need not drop your keys very far away in a parking lot before they become impossible to find.
caf 7y ago
Several galaxies have angular diameters when viewed from Earth of more than 1 degree. The Large Magellanic Cloud is 11 degrees! None of the planets in our solar system are anywhere near this big in the sky - the Moon is only half a degree. Getting a brighter picture of something that's dim just requires collecting more light - essentially taking a longer exposure. But getting a sharper picture of something that's very small in the sky is limited by both the aperture of the telescope (the diffraction limit) and the atmospheric distortion, if you're viewing from the ground.

jcims 7y ago

That and including a standard scale for apparent width. I always thought that photos of other galaxies resolved into specks the size of stars in the night sky. This composite of Andromeda and the moon blew my mind: https://apod.nasa.gov/apod/ap061228.html https://apod.nasa.gov/apod/ap061228.html

TeMPOraL 7y ago
Holy hell, thank you for that! I was under the same impression as well. The photo just made me appreciate how big the galaxies are!
sandworm101 7y ago
But that isnt what you would see by eye or even a normal telescope. That is a long-exposure image. By eye you can only see the brighter/smaller core. Get a more sensitive camera, something able to see the diffuse gas and dimmer stars, and andromeda would be twice even that size.
- Fernicia 7y ago
  I don't think anyone is under the impression that image can be seen with the naked eye.
  - jcims 7y ago
    You're right! But I tried tonight just to see if it was possible to see anything at all. My eyes are kind of shitty but we live out in the boonies with no light pollution. There's a little 'yellow brick road' of stars that lead you to it and if i looked slightly aside i could juuuuuuuuust make out the slightest smudge where it is supposed to be. It was right on the edge of my ability to perceive it, need to try again after spending an hour in the dark.
- misterprime 7y ago
  I think the goal is to get a better sense of "how much of my visual space would this object occupy if I could see it". I had no idea Andromeda would appear larger than the moon from here if I could see it with my naked eyes. That really helps me get a sense of the size. "Wow, it's that large even though it's that far away!?"

caymanjim 7y ago

> The astronomical news community would do the public a very big favor if they started stating clearly which pictures are taken by telescopes and which are cgi. I agree that there ought to be clearer indications of which images come from sensor data and which are purely simulated, but all sensor images are heavily processed. I worked on Mars Global Surveyor, Mars Odyssey, MRO, LRO, and other NASA missions, and wrote image processing software for various instruments on those spacecraft (primarily infrared cameras). They're not simply snapshots like you'll get from your DSLR. Even the most DSLR-like cameras tend to image in many spectral bands (e.g. 11 bands ranging from infrared through visual into UV). An image you see in a magazine typically selects three spectral bands and assigns them to red, green, and blue. Almost none of the images you see are true color, in part because almost none of the instruments have 3-band RGB sensors like you might see in your DSLR. There are many reasons for this, but the two biggest ones are that much of the universe is opaque to visual frequencies (you need infrared or other sensors to penetrate clouds of dust), and much of the scientifically interesting data isn't present in the visual spectrum (infrared is used to determine mineral composition, like finding hematite on Mars, which is evidence of water in the past). Images of the surface of planets comes from a complex stitching-together of long, thin strips of data (again in many non-visual frequencies), which are taken from different angles, at different times of day. In order to create the uniform, visually-appealing (and also scientifically-valuable) images of the surface of Mars that you see, the images are heavily processed to balance albedo and adjust other anomalies. One little-known fact is that gravitationally, none of the large, rocky celestial bodies are spherical; the moon in particular is a very lumpy potato shape. This means that an orbit around the moon is nowhere near a perfect ellipse; it wobbles up and down all the time, which means the distance of the camera from the surface changes all the time. All of this has to be compensated for. During processing, everything is stretched to align, and hundreds/thousands of images of the same region from different times (over many years) are averaged together to get the final product. All of this is a long way of saying that literally every astronomical image you've seen is computer-generated and heavily processed. There's value in knowing which images started with sensor data and which are pure simulation, but there's no value in non-computer-generated imagery. It's hard to explain this quickly in an image caption. We used to have to deal with conspiracy quacks all the time, demanding that we release the "real images" rather than our "manipulated images" so that they could find the aliens on Mars, but the simple truth is that there are no "real images". It's all sensor data in a form that is completely useless without extensive processing.