(Submitted January 17, 1999)
I'm in 12th grade and plan to major in
astrophysics in college. But I was wondering, what are problems with
ground-based telescopes? Why is the HST more effective than telescopes on
The short answer is that ground-based telescopes have to look through
the Earth's atmosphere. The stars appear to twinkle when we look up at
the night sky because their light has to pass through air which is moving
and is at different temperatures, and thus has different refractive
indices. To get a clearer view, the Hubble Space Telescope was placed in
orbit, above the Earth's atmosphere.
You can find out more about the
Hubble Space Telescope at: http://www.stsci.edu/.
Damian Audley and Sean Scully
for Ask an Astrophysicist.