The Universe

The universe is the largest thing in, well, the universe. It encompasses everything that we know, big and small, and contains the laws of physics. It was born in the Big Bang in a massive, powerful expansion that is still continuing to this day. People still do not know whether the universe is finite or infinite, but whichever is the case, the universe is still huge.

The Galaxy Cluster

We exist in the Milky Way, a spiral galaxy that is part of a larger group of galaxies called the local group. The local group is a large collection of our local "neighborhood" galaxies, including a galaxy called the Andromeda Galaxy. This galaxy in particular is due to collide with the Milky Way in around 5 billion years, eventually merging with our own galaxy.

The Milky Way

The Milky Way is our local galaxy. It contains around 100 billion stars and is a spiral galaxy, meaning that its centrifugal motion has thrown its arms outwards in a spinning way, hence the name. You can occasionally see it in the sky as an enormous band of countless white stars streaking across the night sky.

The Solar System

The Solar System is a small group of planets orbiting our star, the Sun. Many stars in the Milky Way have a similar composition, with a star in the center and several planets orbiting it. The Sun actually makes up over 95% of the whole solar system, and the rest is composed of the planets and the asteroid belt. The Solar System contains 8 planets, but is unique in that it has Earth, the only known planet to have life.


The Earth is our home planet, and is the fifth largest planet in the Solar System. It lies in a region of space called the Goldilocks Zone which is the special area where the Sun's heat is not too extreme or too scarce in order for life to exist. Its surface area is composed of about 70% water and 30% land. The Earth is the most important planet to use, as it is the only place which we currently know of that is able to host life forms and liquid water. An interesting fact is that the Moon is actually a piece of Earth that was hacked off during a celestial collision between Earth and an unknown asteroid.


Humans are possibly one of the most influential species on the surface of the planet. We are the only known life forms to have gained self-consciousness and we are able to construct complex structures and develop socioeconomic heirarchies the likes of which no one has ever seen. Unfortunately, human presence on the Earth is causing many problems as well. Humans have a bad habit of filling the air with carbon dioxide which in turn causes the sky to heat up through the greenhouse effect. We also sometimes take the planet for granted by killing all the animals we want, but sometimes we need to remember that we share the planet, not own it.