Mirror from the Great Rosse Telescope

Lord Rosse’s huge telescope in the Irish midlands was the largest in the world for over 70 years. This six-foot mirror allowed him to gather enough light to examine faraway items, particularly the hazy patches of sky that had been puzzling astronomers for years.

Rosse was able to see that some patches were made up of a spiral structure. We now know that these are galaxies beyond our own.