Telescope

The limits to the resolution of a telescope are, as described above, a result of the passage of the light from the distant body through the atmosphere which is optically nonuniform. Stars appear to twinkle because of constantly fluctuating optical paths through the atmosphere, which results in a variation in both brightness and apparent position. Consequently, much information is lost to astronomers simply because they do not have sufficient resolution from their measurements. There are three ways of overcoming this limitation, namely setting the telescope out in space in order to avoid the atmosphere altogether, compensating for the distortion on a ground-based telescope and/or stellar interferometry. The first two methods are innovations of the 1990s and are expected to lead to a new era in observational astronomy.