... Nearly 400 years ago astronomer Johannes Kepler observed comet tails blown by a solar breeze and suggested that vessels might likewise navigate through space using appropriately fashioned sails. ... The Star Trails of Kilimanjaro . ... After last month's dramatic swoop past the Sun, Comet NEAT (C/2002 V1) appeared as a naked-eye comet, emerging from the evening twilight in planet Earth's southern skies. ... In the Center of the Lagoon Nebula . ... Will the Universe End in a Big Rip . ... Stereo Eros...