Preat on Museums
What is the Universe?
The universe is everything. It includes all of space, and all the matter and energy that space contains. It even includes time itself and, of course, it includes you. Earth and the Moon are part of the universe, as are the other planets and their many dozens of moons. Along with asteroids and comets, the planets orbit the Sun. The Sun is one among hundreds of billions of stars in the Milky Way galaxy, and most of those stars have their own planets.
The Universe contains billions of galaxies, each containing millions or billions of stars. The space between the stars and galaxies is largely empty. However, even places far from stars and planets contain scattered particles of dust or a few hydrogen atoms per cubic centimeter. Space is also filled with radiation, magnetic fields and high energy particles. The Milky Way is but one of billions of galaxies in the observable universe — all of them, including our own, are thought to have supermassive black holes at their centers. All the stars in all the galaxies and all the other stuff that astronomers can’t even observe are all part of the universe. It is, simply, everything.
There is so much about space, our solar system, and the galaxy that we still don't know! Space is vast. With billions of galaxies and stars, and planets in our own solar system yet to be fully explored or understood, scientists' knowledge of space is always evolving. There are, however, some really cool things we know about space right now! We've compiled a list of what we think are ten stellar facts that we hope you'll think are out of this world!
interesting facts about the universe and its surroundings
space is completely silent
the sun’s mass takes up 99.86% of the solar system.
there are more trees on earth than stars in the milky way
the sunset on mars appears blue
there are more stars in the universe than grains of sands on earth
one day on Venus is longer than one year.
How big is the universe?
No one knows the exact size of the Universe, because we cannot see the edge – if there is one. All we do know is that the visible Universe is at least 93 billion light years across. The Universe has not always been the same size. Scientists believe it began in a Big Bang, which took place nearly 14 billion years ago. Since then, the Universe has been expanding outward at very high speed. So the area of space we now see is billions of times bigger than it was when the Universe was very young. The galaxies are also moving further apart as the space between them expands.
By Valerie Cuello, Step 8 Yellow
