Ursa Major, or Great Bear, the constellation in the northern skies that contains the Big Dipper, a name suggested by the shape of the figure formed by its seven brightest stars. In mid-northern latitudes Ursa Major remains above the horizon day and night the year round. It can therefore be seen on any clear night.
A look at the night sky at any time of year will reveal a faint band of light stretching across the sky -- our solar system's home, the Milky Way. How much do we really know about it?
Killer asteroids are all fun and games -- until they're headed for Earth. How do we stop cosmic hot potatoes from wiping out our planet?