“We sail within a vast sphere, ever drifting in uncertainty, driven from end to end.” -Blaise Pascal
By now, you've probably learned that Messier objects -- and galaxies in particular -- come in a huge, rich variety of types, structures and compositions. But sometimes, the simplest structure of all is the rarest.
Image credit: © 2006 — 2012 by Siegfried Kohlert, with M89 (left) and M90 (right) together, via http://www.astroimages.de/en/gallery/M89.html.
Think about it: most galaxies are classified as spirals, ellipticals or irregulars. But when was the last time you heard of a spherical galaxy? Never? That's because there are so few, they're just classified as an oddball among ellipticals. Well, that's exactly what the deal is with Messier 89!
Image credit: NASA / ESA / Hubble Space Telescope, via Wikisky.
Go read the whole story -- historical, physical and pictorial -- of this fantastic and unique object!