Observing

Why do eclipses happen?

Solar eclipses are relatively rare; they happen when the Moon moves directly and precisely in front of the Sun. Why are they so infrequent, and why do solar eclipses always come in pairs with lunar eclipses?

News

Hubble at 30: A cosmic legacy

Amid flame and smoke, the Hubble Space Telescope blasted off the launch pad aboard the space shuttle Discovery 30 years ago today, ushering in a new era for astronomy that has transformed our understanding of the Universe around us.