Astronomy (Up) | See also: Physics Web resources Is the Moon moving away from the Earth? When was this discovered? (Intermediate) - Curious About Astronomy? Ask an Astronomer ★ APOD: 2013 February 20 - Saturn's Hexagon and Rings ★ How has knowledge of fusion of the Sun changed astronomy? ★ Do all galaxies have a blackhole in the center ★ What keeps galaxies together? ★