By Alvin Alexander. Last updated: March 24, 2018
Mashable asked astronauts if they think aliens exist. Here’s part of the article I found interesting:
“The math isn’t easy. How many stars are in the universe? Well, that depends on the size of the universe. We’re able to observe the cosmic microwave background (CMB), radiation formed around 400,000 years after the Big Bang. It tells us the observable universe goes back around 14 billion years. But there could be something beyond the CMB, or even other universes contained in a massive ‘multiverse.’”
“Within the constraints of the observable universe, there could be 1,000,000,000,000,000,000,000,000 (or septillion) stars, according to astronomer David Kornreich. (He conceded to Space.com that the number could be a gross underestimate.)”