Download Stellarium, to observe the skies
Stellarium is free GPL software which renders realistic skies in real time with openGL. With Stellarium, you really see what you can see with your eyes, binoculars or a small telescope. Stellarium is also used in planetariums.
Features: Look around by mousedragging, or moving your mouse against the edges of the window; Time control: forward, backward, return to present; Zoom; Tabbed configuration windows; Text user interface: minimalistic menu for use with dome projections; Clickable world cities map to set coordinates; Save your default location; All stars from the Hipparcos catalogue; The planets of our solar system, and their natural satellites; All Messier objects; All NGC objects; Planet orbits; Cardinal points; Azimuthal grid; Equatorial grid; Ecliptica; Equator line; Meridian line; Moon scaling; Object trails; Asterisms and names of the constellations; Constellation boundaries; Compensation for light travel time; Equatorial/azimuthal mount; FOV; Disc viewport; Observation from another planet, and as solar system observator; Fisheye projection; “old_style” projection, i.e. a ground texture and a number of side textures; Spherical panorama projection; Constellation art for the 88 Western constellations stemming from Greek mythology, and 11 for the Inuit sky culture; Realistic atmosphere; Fog near the earth’s surface; Star twinkling; Meteor showers; Full screen or windowed mode; Perspective projection; Fisheye projection; Stereographic projection; Spherical mirror projection; True Type font rendering; Frames per second display; Frame rate limiter; Gravity labels for use in a dome; Light pollution simulation loosely callibrated to the Bortle Dark Sky Scale; Eye adaptation simulation; Sky culture: Western, Chinese, ancient Egyptian, Polynesian; Sky localization; Application localization.
(Check also Full Moon Desktop Gadget)