Frequently Asked Questions About Astronaut-Acquired Photographs

Questions about access to photographs:

How many photographs have been taken?
How do I see some examples of the photographs with information on the locations pictured?
How can I do a thorough search of the entire database of photographs?
How can I get my own copies of astronaut photographs?
Do I need special permission to use astronaut photographs or to publish them?

General questions about Earth images:

North is not at the top of the photograph, is there some mistake?
The thumbnail and browse image look terrible, is it really that bad?
Why can't you see stars or galaxies in the photographs that show the curvature of the Earth and part of the black background of space?
Is it true that the Great Wall of China is the only human-made object that can be seen from space?
Where can I find a photograph of the whole Earth as seen from space?
Where can I find pictures of the Earth at night showing city lights?
How can I see pictures of Mount Everest?
Do the photos show the view exactly as it appears to the naked eye out the spacecraft window?

Questions about the descriptive database:

What information is available about each photograph?
What kind of film is used?
What are "nadir," "near vertical," and "oblique" views?

Questions about interpreting the photographs:

How can oblique photos be used?
Is north to the top of the photo?
What areas do the photographs cover?

Questions about digital images:

How do I know if an image on the website is the best possible quality?
How are digital camera images compressed and brought down from orbit?
What kind of color correction is used on images taken with a digital camera?
Can I get a copy of an image at 300 dpi?

Questions about resolution and remote sensing:

What is the resolution of the photographs?
How does the resolution compare with data from robotic satellites like Landsat or SPOT?
What are the smallest objects that can be seen in the photographs?
How does pixel size or instantaneous field of view relate to the size of objects can actually be distinguished in a space photograph?
What is the modulation transfer function for astronaut-acquired images?
Since astronauts are travelling so fast in orbit, why don't the photographs look smeared?

Questions about research and development:

How can I use the photographs in scientific research?
How does this data relate to other programs that NASA has for studying the Earth?
What will be the future of astronaut photography on the International Space Station?