It's Space Week on Short Wave! Today, an encore of our episode on dark energy. This mysterious energy makes up almost 70% of our universe and is believed to be the reason the universe is expanding. Yet very little is known about it. To figure out what we do know — and what it could tell us about the fate of the universe — we talk to astrophysicist Sarafina Nance).Learn more about sponsor message choices: podcastchoices.com/adchoices)NPR Privacy Policy)
