Astronomy for Beginners

Here’s where you’ll find observing guides, how-to articles and great astronomy hints and tips. Don’t forget to also check out our comprehensive astronomy dictionary.

Astronomy Dictionary
Gravitational waves

Predicted in Einstein’s general theory of relativity, these waves are believed to be ripples in the fabric of space-time caused by bodies such as binary systems (binary white dwarfs, neutron stars or black holes). The Laser Interferometer Space Antenna (LISA)
is one of several missions that will hopefully detect gravitational waves.

Eclipse mapping

A technique used to indirectly map the surface of an eclipsing binary star, to look for starspots and make other studies by using Doppler imaging.


The point of closest approach for an object in orbit around the Earth.