Flight

[dadddarrell2]

1 What are Spaced-based obvervations of earth used for?

2 Why is a telescope such as Hubble such a tremendous advantage over earth-based telecopes?

3 What evidence do astronomers look for to indicate the formation of a new stat?

[gary baldy]

I think the answers to 1) are many (not enough room to go into here). I suppose mainly for weather and environmental predictions. There are of course spy satellite aswell. For 2) the advantage is that the earth's atmosphere is full of pollution (both natural and man made) and other distractions that hinder earth based telescopes. Once you are past the earth's atmosphere it is just the empty vacumn of space for the light to travel through so you get much, much better images. Dont know about 3). sorry!

[einsteinsdog]

Question 3 is unintelligible ?

[bernardo]

3. A new star is formed gradually where there is a large cloud of gas and material which is gradually condensing. Blobs of stuff gradually coalesce under the force of gravity, and when the blobs get big and heavy enough they start to burn inside and glow and become stars. It's a process which happens over hundreds of millions of years, so it's not a specific single event like an explosion. They just look for big clouds (nebulae).

[stevie21]

for #2 - even without pollution, there's also clouds and the earth's atmosphere which occlude or blur what you see.
If you're looking at a star that's near the horizon then the light from it comes to you though the atmosphere at an angle and has to go through more atmosphere to get to you (blurring your vision more). e.g in this picture the distance, in green, that light goes through the atmosphere to or from the sun differs greatly on different bits of the earth.

[CT]

1, Only optical, radio and some wavelengths of infrared EM radiation are observableon the surface of the earth. Gamma-ray, X-ray, Ultra Violet(UV), Mid-Far Infrared, are only observable in space.
*Well some x-ray can be observed in high atmospheric balloons, but the best observations come from space*

[jake-the-peg]

Careful CT Question 1 says observations of Earth so the U/V X-ray answer is wrong here.

Question 2 Says Like Hubble So it's wrong here too!

It's a good answer just not to the actual questions here.

Only other thing I have to add is to 1)They are used for Spying

You dont think that Hubble doesn't have a brother looking down do you?

[CT]

The fact that 2, said advantage over Earth based telescopes led me to believe that the question was after astronomical observations. Can't really use earth based telescopes to view very much here on earth.