Far out in the uncharted backwaters of the unfashionable end of the western spiral arm of the Galaxy lies a small unregarded yellow sun. Orbiting this at a distance of roughly ninety-two million miles is an utterly insignificant little blue green planet whose ape-descended life forms are so amazingly primitive that they still think digital watches are a pretty neat idea, Douglas Adams, The Hitchhiker’s Guide to the Galaxy.
Geology is the study of the earth, geo means earth and ology means study of. It’s concerned with the solid Earth, its history, shape, the materials of which it is made, and the processes that are acting and have acted on it. Astronomy is the study of the universe. It includes Earth and everything that lies outside of its atmosphere, such as planets, stars, galaxies, comets, and black holes.
The Earth is the fourth planet away from the Sun . The Solar System is the sun and everything that orbits or moves around it due to its gravity. It is a collection of planets, moons, asteroids, comets, dust and gas. It is situated within the Orion-Cygnus Arm of the Milky Way galaxy.
You may want to read our free ebook The Solar System for a brief introduction to this topic.
The Solar System includes:
The sun itself. It is a 4.5 billion-year-old yellow dwarf star made mainly out of hydrogen and helium. It is, by far, the biggest and heaviest celestial body in the Solar System. It contains more than 99.8% of the total mass of the Solar System. It is not passive, it has flares and coronal mass ejections which are powerful eruptions of plasma on the Sun’s surface. These eruptions can have widespread impacts on Earth, such as disrupting power grids and communications networks or damaging satellites.
A planet is a spherical celestial body that does not produce light and orbits around a star. The solar system has eight planets which are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Moons are solid celestial bodies that orbit planets.
Celestia is a real-time space simulation that lets you explore our universe in three dimensions. It is free, open source, and multiplatform.
Cometsare small and icy celestial bodies that orbit around the sun. They are cosmic snowballs of frozen ice, rock, and dust. When they approach the sun, the ice starts to heat up and turn into gas. The water vapor and dust released by the heating process form their long tails.
Asteroids are small, rocky worlds without atmospheres that revolve around the sun. The larger ones are called planetoids or minor planets. Despite their size, asteroids can be pretty dangerous.
Do you like astronomy? Read our article Astronomy Free Software that compiles and describes a list of educational apps, completely free that help you to learn more about the Solar System, the Milky Way, and the Universe.