Hey guys welcome to the next APES blog post! This is going to a an astronomy sub-series.
Our universe contains billions of galaxies, groups of millions of starts held and bound by gravitational forces. Our galaxy is the milky way galaxy. Gravity forms planets and stars by forcing and moving around dust clouds and debris particles around in space.
The universe’s formation is based off the big bang theory, explaining how it developed from a dense singularity, or a point of infinity. This point has expanded over the billions of years in time. The universe is 13.7 billion years old.
But how do we know the universe is expanding? Edwin Hubble, 1929, said that the universe is expanding through the Doppler Shift effect. As stars move away from the Earth they begin to dim, this is the red shift. As stars move towards the Earth, there is a blue shift.
Types of galaxies are spiral, irregular, and elliptical. Spiral tend to contain young stars and are blue in color. Elliptical are reddish with older stars. Irregular galaxies have no singular defined shape or color. Super-clusters are large cluster of galaxies.
Our Solar System is made up of our planets and the sun. Copernicus in the 1400s proposed that the planets orbit the sun, also known as the heliocentric theory, which was opposed by the Church’s geocentric theory that the planets and sun revolved around Earth.
The Nebular theory states that our system formed from large rotating dust and gas clouds. These gases condensed from a nebula which is a large gas cloud. Our system is 4.6 billion years old.
The planets in our system exist in this order: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. The terrestrial planets are the first four and are rocky, smaller, and solid. The farther four are Jovian planets and are larger with more gaseous surfaces.
Lastly there are three planetary motion laws created by an astronomer named Kepler. The three are:
- The orbit of all planets are an ellipse with the sun as the center
- Planets move the fastest closer to the sun and slowest farther away
- The orbital period around the sun of a planet correlates to the distance from the sun
Thank you and make sure to read the rest of the series! 😀
Written By: Neil 7/15/2019