Narrator: This is Science Today. Scientists have discovered that the universe is expanding at an accelerating rate, but little is known about the Dark Energy that causes this phenomenon. Greg Aldering, an astrophysicist at the Lawrence Berkeley National Laboratory, says studying supernovae could be our greatest lead.
Aldering: This Dark Energy makes about 70% of the universe. And so it's this thing that we don't know what it is, we know how it has made the universe expand. And it's 70% of the universe, so it's this big unknown. And so we're really excited about trying to figure out what it really could be.
Narrator: Aldering says that by identifying larger samples of supernovae, we can map out how the universe has expanded.
Aldering: So the essence of the experiment is to look at the supernovae nearby, look at them very far away, and compare the ratio of their brightnesses. This gives us a ratio of their distances, which is all we need to measure the expansion history.
Narrator: For Science Today, I'm Larissa Branin.