New Theory on How Spiral Galaxies Got Their Arms

Ever since astronomers started differentiating between spiral and elliptical galaxies, they have wondered what precisely makes some galaxies develop their trademark arms, while others remain without them. Our own galaxy, the Milky Way, is a spiral one, featuring two, or, according to new stud... [ read more >> ]

The Pinwheel Galaxy, showing off its remarkable spiral arms

Image comment: The Pinwheel Galaxy, showing off its remarkable spiral arms
Image credits: NASA / ESA

The Pinwheel Galaxy, showing off its remarkable spiral arms