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Q:
Why are the Chandra and the VLA telescopes different in size but have simliar resolutions? Are there any
other telescopes that are a 100x better than both of them?
A:
Chandra is sensitive to x-ray wavelengths and the
VLA is sensitive to radio wavelengths. These 2 types of radiation
require very different methods for detecting them. Chandra needs long
smooth mirrors made of iridium so that the high energy x-rays will not
penetrate the mirrors, and instead will glance off and be focused onto
the detectors at the base of the telescope. Radio radiation is
detected in a much different way, using many large dishes spread over a
large area. Radio waves are easier to detect for 2 reasons - radio
waves are not absorbed by the Earth's atmosphere, so we can place radio
telescopes in the ground instead of up in orbit like Chandra. And,
radio radiation has much lower energy than x-rays, so it won't
penetrate material like x-rays do. The technology for detecting each
type of radiation is therefore very different.
There is no telescope, past or present, that has ever had a better
angular resolution in x-rays than the Chandra telescope. The
VLBI (Very Long Baseline Interferometry) might have a better resolution than
the VLA but you'll have to look at their website to check this. Try going to Google (http://www.google.com) and searching on the
keywords VLBI and VLA for answers.
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