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Space Shuttle and ISS transit the Sun.

petercooper 16y ago
Astronomy types.. how comes the Sun looks so smooth and simple in this picture whereas it looks almost "volcanic" and highly irregular in most other pictures I've seen? (Just do a Google Images search for "sun" to see loads of them.)
- ubernostrum 16y ago
  This page gives a bit more explanation, particularly the filters used on the camera (which would be a necessity to reduce the glare and intensity of the sun enough to resolve something like the ISS + shuttle): http://www.astrosurf.com/legault/iss_atlantis_transit_2010.html http://www.astrosurf.com/legault/iss_atlantis_transit_2010.h...
- jordanb 16y ago
  The sun probably isn't in focus. I don't know what infinity is for a lens like that, but it's probably further away than LEO.
- mturmon 16y ago
  The simple reason is that the photo was imaged with a filter that admitted a wide band of spectrum ("continuum" or "white light"). The science images you see are with very narrow filters, which pass light of a very-very specific color. These filters are typically about 1nm wide, the range of visible light is hundreds of nm (380-750nm). The Sun emits a lot of photons, so it's no problem to filter them out. Why do they look in these narrow bands? When you do so, you see only plasma at a certain temperature range -- by varying where the tiny passband is, you see different cross sections of heated plasma. This turns out to be very useful to understand the solar atmosphere and in particular the corona; the coronal heating problem (http://en.wikipedia.org/wiki/Corona#Coronal_heating_problem http://en.wikipedia.org/wiki/Corona#Coronal_heating_problem) is the major unsolved problem in solar physics. A good scientific explanation of the remote sensing problem is at: http://aia.lmsal.com/public/firstlight.html http://aia.lmsal.com/public/firstlight.html The story of these bands is fascinating. See http://en.wikipedia.org/wiki/Astronomical_spectroscopy http://en.wikipedia.org/wiki/Astronomical_spectroscopy and http://en.wikipedia.org/wiki/Fraunhofer_lines http://en.wikipedia.org/wiki/Fraunhofer_lines As a teaser, before the quantization of spectra was known, it was considered impossible to ever know the chemical composition of the Sun. What are you going to do, land there and take a sample back to the lab? Shortly thereafter, spectroscopy was understood and helium was discovered on the Sun (helium -- helios) before being isolated on Earth. The laugh was on the pundits, and now we know the composition of stars all over the galaxy.
pencil 16y ago
kinda unbelievable..no sun spots or any other form of solar activity
- mturmon 16y ago
  On that day, there were no visible sunspots: http://soi.stanford.edu/production/gif_images/intensitygrams/2010/May//MDI_int_2010.05.16_06:24.rotated.gif http://soi.stanford.edu/production/gif_images/intensitygrams... But, a week later when it made APOD, there was a big one: http://soi.stanford.edu/production/gif_images/intensitygrams/2010/May//MDI_int_2010.05.23_11:12.rotated.gif http://soi.stanford.edu/production/gif_images/intensitygrams... Here's a very active day from a peak in the last cycle: http://soi.stanford.edu/production/gif_images/intensitygrams/2001/September//MDI_int_2001.09.23_03:12.gif http://soi.stanford.edu/production/gif_images/intensitygrams... These are not true white-light images, but they are approximations. Also, their contrast has been enhanced.
alexforget 16y ago
deepzoom version of the same kind of stuff http://alex.bouncingbox.com/iss/ http://alex.bouncingbox.com/iss/
Estragon 16y ago
I saw this when it came out and thought "someone's been reading Anathem"
ugh 16y ago
Those Astronomy Pictures of the Day are well worth exploring. Here is the Moon and Venus as you might not have not have seen them before (well, at least Venus): http://apod.nasa.gov/apod/ap100516.html http://apod.nasa.gov/apod/ap100516.html
sachbh 16y ago
wow! great picture
praeclarum 16y ago
Fantastic photo. Now if only we had the foresight to make the ISS more substantial. It looks like a bug ready to be squashed. Makes me think we're in the dark ages of space research, a long ways from the eventual renaissance.

Astronomy types.. how comes the Sun looks so smooth and simple in this picture whereas it looks almost "volcanic" and highly irregular in most other pictures I've seen? (Just do a Google Images search for "sun" to see loads of them.)

ubernostrum 16y ago
This page gives a bit more explanation, particularly the filters used on the camera (which would be a necessity to reduce the glare and intensity of the sun enough to resolve something like the ISS + shuttle): http://www.astrosurf.com/legault/iss_atlantis_transit_2010.html http://www.astrosurf.com/legault/iss_atlantis_transit_2010.h...
jordanb 16y ago
The sun probably isn't in focus. I don't know what infinity is for a lens like that, but it's probably further away than LEO.
mturmon 16y ago
The simple reason is that the photo was imaged with a filter that admitted a wide band of spectrum ("continuum" or "white light"). The science images you see are with very narrow filters, which pass light of a very-very specific color. These filters are typically about 1nm wide, the range of visible light is hundreds of nm (380-750nm). The Sun emits a lot of photons, so it's no problem to filter them out. Why do they look in these narrow bands? When you do so, you see only plasma at a certain temperature range -- by varying where the tiny passband is, you see different cross sections of heated plasma. This turns out to be very useful to understand the solar atmosphere and in particular the corona; the coronal heating problem (http://en.wikipedia.org/wiki/Corona#Coronal_heating_problem http://en.wikipedia.org/wiki/Corona#Coronal_heating_problem) is the major unsolved problem in solar physics. A good scientific explanation of the remote sensing problem is at: http://aia.lmsal.com/public/firstlight.html http://aia.lmsal.com/public/firstlight.html The story of these bands is fascinating. See http://en.wikipedia.org/wiki/Astronomical_spectroscopy http://en.wikipedia.org/wiki/Astronomical_spectroscopy and http://en.wikipedia.org/wiki/Fraunhofer_lines http://en.wikipedia.org/wiki/Fraunhofer_lines As a teaser, before the quantization of spectra was known, it was considered impossible to ever know the chemical composition of the Sun. What are you going to do, land there and take a sample back to the lab? Shortly thereafter, spectroscopy was understood and helium was discovered on the Sun (helium -- helios) before being isolated on Earth. The laugh was on the pundits, and now we know the composition of stars all over the galaxy.

pencil 16y ago

kinda unbelievable..no sun spots or any other form of solar activity

mturmon 16y ago
On that day, there were no visible sunspots: http://soi.stanford.edu/production/gif_images/intensitygrams/2010/May//MDI_int_2010.05.16_06:24.rotated.gif http://soi.stanford.edu/production/gif_images/intensitygrams... But, a week later when it made APOD, there was a big one: http://soi.stanford.edu/production/gif_images/intensitygrams/2010/May//MDI_int_2010.05.23_11:12.rotated.gif http://soi.stanford.edu/production/gif_images/intensitygrams... Here's a very active day from a peak in the last cycle: http://soi.stanford.edu/production/gif_images/intensitygrams/2001/September//MDI_int_2001.09.23_03:12.gif http://soi.stanford.edu/production/gif_images/intensitygrams... These are not true white-light images, but they are approximations. Also, their contrast has been enhanced.

alexforget 16y ago

deepzoom version of the same kind of stuff http://alex.bouncingbox.com/iss/ http://alex.bouncingbox.com/iss/

Estragon 16y ago

I saw this when it came out and thought "someone's been reading Anathem"

ugh 16y ago

Those Astronomy Pictures of the Day are well worth exploring. Here is the Moon and Venus as you might not have not have seen them before (well, at least Venus): http://apod.nasa.gov/apod/ap100516.html http://apod.nasa.gov/apod/ap100516.html

sachbh 16y ago

wow! great picture

praeclarum 16y ago

Fantastic photo. Now if only we had the foresight to make the ISS more substantial. It looks like a bug ready to be squashed. Makes me think we're in the dark ages of space research, a long ways from the eventual renaissance.