(All the text of the latter is actually taken from the former, but the UI is kinda ridiculous. The first bit is from the initial "Introduction" tab; for the rest, go to the "Release Images" tab and click on individual ones; each is associated with some text.)
anyone know why not?
I suspect that the answer is that the cameras are designed to look into some of the deepest darkest regions of space, and are freakishly sensitive. So much so that keeping the cameras at frigid temperatures is a requirement in order to make sense of the signal they collect. Pointing it at the sun, I would assume, would be at best unusable, and at worst damaging.
For some perspective - look up the NICMOS camera:
There was a thermal short in the cooler that threatened it's life span, so they cooked up an external cooling system in order to keep the camera at some absurdly cold temperature like 60 Kelvin. (I could be wrong about the temp - but it's COLD).
So I looked into it. Wikipedia explains that the Sun is never allowed to illuminate any part of the Optical Telescope Assembly. And therefore Hubble never points within 50 degrees of the Sun. This is the "Solar Avoidance Angle". A forum on NasaSpaceFlight.com has a message that adds more detail:
In general the following viewing constraints apply:
- 50 degree solar avoidance angle
- 20 degree from illuminated Earth
- 6 degree from dark Earth limb
I don't know this, however. Further info from someone knowledgeable, would be nice.
> Most HST observations are made when the target is roughly 90 degrees from the sun. However, scheduling constraints can force the observation into other sun angles.
> The brightest backgrounds result when sources in the ecliptic plane are observed close to the sun. If you are concerned about the worst-case sky background, you may wish to try setting "sun angle" to 50 degrees, which is the HST solar avoidance angle. Ecliptic longitudes less than 50 degrees are possible for sources far from the celestial equator, but for these sources the zodiaical light is already moderately low.
> The lowest backgrounds occur when sources are farthest from the sun, i.e., "sun angle" = 150 to 180 degrees.
Well, replace the ant with a zillion dollars' worth of ultra-sensitive cryogenic CCDs and scale up the magnifying glass by a factor of a lot.