All the astrophysics nerds are still trying to figure that out!
So the universe is made of of 5% known stuff (atoms), 25% dark matter and 70% dark energy.
Atoms are planets, suns, stars, galaxies – things we can observe and interact with because they have protons, neutrons and electrons.
Dark matter is this invisible thing that we know exists but can’t measure because it doesn’t interact with atoms so it can’t be measured by any of our instruments.
Dark energy is every crazier – we know it makes up most of the universe and it is a force that repels gravity but again, no way to observe it yet.
ESA’s Planck Mission gave us the best picture we have ever seen yet of the universe (like 100times better than NASA’s previous best picture) http://www.esa.int/Our_Activities/Space_Science/Planck and that’s how we know lots more things now about dark matter.
Astrophysicists have lots of ideas about dark matter and dark energy, but noone knows what they really are like yet – unsolved mystery for future space scientists!
Comments