Messier Monday: A Spectacular Solstice Spiral, M91 (Synopsis)

“It suddenly struck me that that tiny pea, pretty and blue, was the Earth. I put up my thumb and shut one eye, and my thumb blotted out the planet Earth. I didn’t feel like a giant. I felt very, very small.” -Neil Armstrong

When you think about the faintest object in the Messier catalogue -- which happens to be an extended, low-surface-brightness galaxy -- you probably don't think that looking for it on one of the shortest nights of the year just after a full Moon is ideal. Yet, in the case of Messier 91, that may well be the best time to look for it!

Image credit: © 2006 — 2012 by Siegfried Kohlert, via Image credit: © 2006 — 2012 by Siegfried Kohlert, via

The nights will be relatively warm, the Moon doesn't rise until midnight, but most importantly, the galaxy will be as close as it gets to directly overhead in the early part of the night, giving it the advantage of being silhouetted against the blackest parts of the skies you'll have all year.

Image credit: NOAO / AURA / NSF, via Image credit: NOAO / AURA / NSF, via

What else can we learn about this remarkable object? Go read the whole story and find out!


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