Astroengineering is name given to the construction of megastructures in space by technologically advanced beings. It is a form of megascale engineering, but deals with structures that are "easily observable" from interstellar or even intergalactic distances with 20th century astronomical instruments. For instance, an Orbital elevator is an example of megascale engineering, but not of astroengineering. Typically proposed feats of astroengineering are on the scale to remake an entire stellar system.