Non-optical telescopes Flashcards
In what ways are radio telescopes similar and differences to optical telescopes??
Parabolic dish works the same as objective mirror of a optical reflecting telescope
Antenna used as detector at focal point instead of eye
Manoeuvrable
How big are radio waves compared to light?
About a million times longer
How big would a radio telescope need to be to have the same resolving power as an optical telescope?
How do scientists get around this?
A million times bigger
Linking lots of them together
What is used in a radio telescope instead of the polished mirror of an optical telescope?
Wire mesh
What advantages are there of using wire mesh?
Construction is cheaper and easier
Why does the dish shape of a radio telescope have to have a precision of λ/20 ?
To avoid spherical aberration
What is the biggest problem with doing astronomy on earth?
Atmosphere stops certain wavelengths from coming through
What 2 waves can be observed on the surface of the earth?
Optical ( a little UV and a little IR)
Radio
Where is the best place to observe infrared radiation?
High and dry places
How do you detect X-rays and Ultra violet radiation?
Strap the UV and X-Ray telescopes to weather balloons or aeroplanes
Where is the ideal place to put your telescope?
In space
How are IR and UV telescopes similar to optical reflecting telescopes?
Use the same parabolic mirror
What’s the same about UV and IR telescopes?
Both use CCDs as radiation detectors
And both use parabolic mirrors
The longer the wave length the ….. its effected by imperfections
Less
How precise does the mirror shape in IR telescopes need to be and why?
Not as precise
Because it’s has a long wavelength so is affected less by imperfections
