Is it true that there are cameras in space that can read the headlines of a newspaper?

Answer 1

The discrimation (ability to separate elements) of a camera depends on the diameter of the lens and the number of sensible elements in the captor. Film (captors are grains of silver halides) have coarse, medium or fine grain. Digital cameras and CCDs have discrete photon counting elements. Let us consider only the lens.

Smallest resolvable angle (alpha) in seconds of arc = 116 / Diameter (in mm). However, atmospheric conditions seldom allow better than 0.5"

The largest lens in space that I know of is 2.4 m in diameter (Hubble Space Telescope) -- it is actually a combination of mirrors, but the calculation is the same. The theoretical discrimination is 0.05" (=0.0000135 degree = 0.000000235 radian).

At an orbit height of 589 km, the theoretical resolution of an object on Earth's surface exactly under Hubble would be 589,000,000 mm * 0.000000235 = 138 mm (5 inches). Difficult to distinguish letters that are less than that size.

Put something like the Hubble down on a 100 km orbit and you could resolve two points separated by 23 mm (close to an inch).

So, if the headline is taller than a couple of inches, then yes, it can be resolved from space.

In fact, even though the effects of the atmosphere should make the task harder, there are tricks whereby computers can take a lot of blurry images and take away the blurriness to detect what is on the picture. With enough pictures, they can even go beyond the discrimination of the lens.

So, with big enough headlines: possible.

Answer 2

Check out a pretty good URL on telescope resolution:
http://www.licha.de/astro_article_mtf_telescope_resolution.php
You can perform the calculations and find out that for a resolution of an arc sec of a degree you are already at pretty large numerical apertures. At a resolution of 0.2 of an arc sec, or a micro-radian, you could place your observatory at a distance D, such that you could resolve an object with the dimensions of d=0^-3 m according to the following relation:
d/D ~ 10^-6 ==> D=10^3 m. That's no much! On top of this you'd have atmospheric issues which will only make it worse.
The state of the art as claimed by NASA for a 250 mm lens places the smallest object that can be resolved at 8 m from a distance of a few hundred kilometers.
http://eol.jsc.nasa.gov/Faq/res.htm#three

Answer 3

i'm not sure about the newspaper headlines, but I do know that you can go to Google Earth and put in your home address and zoom in so close that you can see a picture of your car parked in the driveway of your house. Its really neat, but at the same time, kinda creepy.

Answer 4

Yes, military spy satellites have the capability of reading a wristwatch from orbit. That's a SERIOUS lens.

Answer 5

they (man made satellites) only can take a photo of newspaper headlines but cannot read it..

Answer 6

Yes there are.

Answer 7

If I told you the truth I'd have to kill you.

Answer 8

yes and they are watching you right now

Answer 9

not yet

Answer 10

No.