Karina Sharma
The spiral arms can be wound tightly or loosely, and some cannot be seen from Earth because we view the galaxy from the side, edge on.
Elliptical galaxies have shapes that range from completely round to oval. They are less common than spiral galaxies.
Lenticular galaxies are a kind of cross between spirals and ellipticals.
Irregular galaxies have unusual shapes, like toothpicks, rings, or even little groupings of stars.
Seyfert galaxies, first identified in 1943 by American astronomer Carl Seyfert, are the most common active galaxies.
Quasars are the most luminous type of active galaxy. They emit light across the electromagnetic spectrum, produce powerful particle jets.