- Mass (Wikipedia)
Mass is an intrinsic property of a body. It was traditionally believed to be related to the quantity of matter in a body, until the discovery of the atom and particle physics. It was found that different atoms and different elementary particles, theoretically with the same amount of matter, have nonetheless different masses. Mass in modern physics has multiple definitions which are conceptually distinct, but physically equivalent. Mass can be experimentally defined as a measure of the body’s inertia, meaning the resistance to acceleration (change of velocity) when a net force is applied. The object’s mass also determines the strength of its gravitational attraction to other bodies.
- Messier 85 (Wikipedia)
Messier 85 (also known as M85 or NGC 4382 or PGC 40515 or ISD 0135852) is a lenticular galaxy, or elliptical galaxy for other authors, in the Coma Berenices constellation. It is 60 million light-years away, and has a diameter of about 36.99 kiloparsecs (120,600 light-years) across.
