Universe, galaxy, and milky way
Galaxy, Universe, and Milky Way
The galaxy is a system of millions or billions of stars, together with gas and dust, held together by gravitational attraction. The milky way is is the galaxy of which the sun and the solar system are a part and which contains the myriads of stars that create the light of the Milky Way. The universe is all existing matter and space considered as a whole; the cosmos.
UniverseThe universe is all existing matter and space considered as a whole; the cosmos. The universe is believed to be at least 10 billion light years in diameter and contains a vast number of galaxies; it has been expanding since its creation in the Big Bang about 13 billion years ago.
|
Galaxy
The galaxy is a system of millions or billions of stars, together with gas and dust, held together by gravitational attraction.
The idea of a galaxy was first realized by Thomas Wright in 1917. |
Milky WayThe milky way the galaxy of which the sun and the solar system are a part and which contains the myriads of stars that create the light of the Milky Way. It is home to planet Earth, the birthplace of humanity. Scientists believe that 90% of our galaxy’s mass consists of dark matter, which gives it a mysterious halo.
|