Radio telescopes are generally smaller than optical telescopes. The radiation from an x-ray telescope presents a health hazard to astronomers. Gamma ray telescopes can be located on the Earth's surface. Infrared telescopes need to be launched into space. Telescopes in space are cheap to construct and easy to maintain.
Spectroscopy is the analysis of the intensity of light at each wavelength.
Smaller size than the jovian planets. More moons than the jovian planets. Higher density than the jovian planets. More closely spaced together than the jovian planets. Between the orbits of Mars and Jupiter.