What is the difference between a galaxy and a nebula? How do astronomers tell them apart?

1 Answer
Jul 13, 2016

Galaxy is a system of widely separated star systems, held together gravitationally. Nebula is a misty cloud of dust and gas, capable of hiding a single or a system of space bodies.


The definitions tell astronomers which is which.

Galaxies are widely separated.

Nebulae can exist within a galaxy.

They are visible in the night sky as a cloud of gas and dust, in outer

space. like a defective patch, in contrast to luminous bodies..