M51 as recorded by Lord Rosse, 1845

M51 as seen through early telescopes

Astronomers using early telescopes saw a fuzzy shape something like this when they looked at the object called M51. All cloudy objects like this were called “nebulae.”

What we can see today

Today, astronomers know that the spiral nebulae, like M51, are actually spiral galaxies composed of billions of stars. This image of M51 shows the bright star clusters that trace the spiral pattern of the galaxy.

Lord Rosse’s 72-inch telescope enabled him to see the spiral shape of the M51 nebula. Like many astronomers, he drew the bright parts of the image with a dark pencil, making his drawing look like a photographic negative.