the univers

the univers

1. On a large scale, the universe is made up of galaxies and groupings of galaxies. ... In addition to stars and their associated stars (planets, asteroids, etc ...), galaxies also contain interstellar matter, made up of dust and gas in a proportion that varies between 1 and 10% of their mass.

2. Therefore, within the Solar System, there are only eight planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune). Pluto, Ceres and Eris (discovered in 2005, formerly known as 2003 UB313 and the trigger for the definition change) become dwarf planets.

3. The space race was a struggle between the United States and the Soviet Union for the conquest of space that lasted approximately from 1955 to 1975. It involved a parallel effort by both countries to explore outer space with artificial satellites, to send humans into space and to the lunar surface.

4. A galaxy (from the Greek γαλαξίας 'lacteal') is a collection of stars, gas clouds, planets, cosmic dust, dark matter and energy gravitationally united in a more or less defined structure. ... Spiral galaxies are circular in shape but with curved arms wrapped in dust.