The vast majority of the universe is comprised of dark energy and dark matter -- less than 5% of the stuff in space is solid, such as stars or galaxies. The commonly accepted proportions of the contents in space are about 68% dark energy, 27% dark matter, and 5% observable solid matter. Dark energy refers to an unknown form of energy that is thought to be responsible for expanding the universe and pulling solid matter apart over long periods of time, while dark matter is matter that cannot be seen because it doesn’t interact with light but is thought to exist due to the fact that its gravitational properties can be measured.
More about space:
- The footprints left on the Moon after the first astronauts stepped on it in 1969 are expected to remain for at least 100 million years.
- The sun is so dense, it makes up approximately 99% of the entire solar system. The amount of energy that reaches Earth from the sun in one hour is less than the planet actually uses in a whole year.
- It would take over 800 years to reach Pluto if it were possible to travel by plane.