What is the nebular theory?
Q: What is the nebular theory?
A: The nebular theory is a process by which solar systems are created. It explains how a large cloud of gas in an area of space can be pulled together by gravity, eventually forming a star like the Sun and planets.
Q: How does the Sun get its energy?
A: The Sun gets its energy from changing hydrogen into helium through a fusion reaction at its core, releasing heat, light and other forms of electromagnetic radiation.
Q: What causes the planets to spin around their own axis?
A: The original gas cloud had different densities in different places, causing it to spin around the Sun and each planet's own axis. This spinning was increased due to contraction under gravity (conservation of energy) and conservation of angular momentum.
Q: Where do all the elements come from that make up terrestrial planets, moons, asteroids etc.?
A: All elements apart from hydrogen and helium come from earlier generations of stars that exploded billions of years ago near our young Solar System - these huge supernovas produced higher elements.
Q: Why do huge stars run through their life cycle much faster than smaller stars?
A: Huge stars have even higher pressures and temperatures inside them as compared with an average main sequence star like the Sun - this causes them to run through their life cycle much faster than smaller stars.
Q: What caused the formation of our Solar System about 4.6 billion years ago?
A: About 4.6 billion years ago there was a large cloud of gas nearby our area of space - all things with mass gravitate towards one another so this pulled all the gas towards the center until it reached high enough pressure for hydrogen atoms to fuse together into helium, beginning our star we know as the Sun.
