Black Hole - a theoretical massive object, formed at the beginning of the universe or by the gravitational collapse of a star exploding as a supernova, whose gravitational field is so intense that no electromagnetic radiation can escape. Galaxies - a large system of stars held together by mutual gravitation and isolated from similar systems by vast regions of space. Dark Matter - matter known to make up perhaps 90% of the mass of the universe, but not detectable by its absorption or emission of electromagnetic radiation

There are many galaxies in the universe, and our galaxy, the Milky Way galaxy, has many solar systems and planets in it. The nearest spiral galaxy, the Andromeda galaxy, is many of the thousands in our universe; they all expand to the outer reaches of space. Another galaxy, The Canis Major Dwarf, was found by German Astronomers on November 10, This is currently the closest galaxy to our own.

Spiral Galaxy- A spiral galaxy has a revolution every 250 million years. Our own galaxy is 175 million more years to have another revolution. Elliptical Galaxy- In an Elliptical Galaxy, the stars have no current rotation, so it cannot have a revolution. Irregular Galaxy- This Galaxy take just as long as a spiral galaxy to have a revolution due to it being a type of spiral galaxy.

Black holes are formed when a supergiant star’s life ends. These pull everything into it with its enormous amount of gravitational pull. massive-black-holes-the-black-hole.html Black holes were fist found in the late 1790s by two astronomers from Germany and France.

If you look at a picture of our universe, you will see a big bright circle. That is called a super massive black hole A black hole will use its gravity to pull and shrink any mass towards itself down to a marble

Dark Matter is impossible to see with the naked eye and even a telescope, but it is there. This is what dark matter would look like if it was blue. Dark matter was found on January of 1937.

It is theoretical that dark matter is just in space, but they are debating whether it is on earth and other planets too.