What is the Goldilocks Zone?

Think of it as the interstellar version of porridge from that old fairy tale, Goldilocks and the Three Bears. It’s that sweet spot around a star where temperatures are not too hot, not too cold, but just right for water to remain as a liquid.

Why all the fuss about liquid water? Well, life as we know it sort of insists on it. That’s why astronomers are basically cosmic real estate agents, hunting for Earth-clones in habitable zones around other stars.

Each star has its own Goldilocks zone depending on its size and heat. Red dwarfs keep things tight while G-type stars (like our Sun) offer a bit more elbow room. But it’s not always straightforward: Mars and Venus technically hang out in our solar system’s habitable zone. Yet Mars is an icebox and Venus is a cosmic sauna where you wouldn’t last a minute without turning into a crispy critter.

The Goldilocks Zone is where we’re putting our bets for finding E.T.