... In space, therefore, we should choose technologies carefully. ... For instance, the solar-photon sail--pushed through space by linear-momentum transfer from reflected solar photons--could carry water mined on comets or hydrated asteroids towards human habitats in dry solar systems. ... Article Highlights New Type Of Astronomy ,,Clubs: Online Amateur astronomers "are beginning to look very different from what they did only a few years ago," an article in last months Sky & Telescope observed. ...