In 1920, astronomers Harlow Shapley and Heber Curtis held a Great Debate. Shapley argued that the spiral nebulae were small and in the Milky Way, while Curtis took a more radical position that they ...

The Andromeda nebula, M31, was a prominent example ... These glass plates recorded images of the night sky using a light-sensitive emulsion covering their surface. The telescope’s size let ...

March is the start of spring in the Northern Hemisphere; with that, the hunt for Messier objects can begin!

NASA’s Spitzer Space Telescope has captured this stunning image of Andromeda Galaxy which is also known as M31. This image, captured by NASA's retired Spitzer Space Telescope, shows only dust which ...

This project might help: OnStep is an open-source telescope controller, a device that controls a telescope to point at something interesting in the sky. Want to take a look at M31? Use an app on a ...