You are here

Exoplanets VI

September 17, 2016

The starship Enterprise began warping around the galaxy 50 years ago this month, discovering new life and new civilizations on just about every planet. But according to researchers in Australia, the real explorers of the future might not be so lucky. They won’t find a bounty of inhabited planets. Instead, they’ll find a bounty of worlds that were inhabited in the distant past, but that now are dead.

The most likely abodes for life are expected to be Earth-like planets orbiting Sun-like stars in the habitable zone — the distance from the star where temperatures are just right for liquid water.

Earlier this year, Aditya Chopra and Charles Lineweaver wrote that such planets probably are common. They even suggested that life is likely to develop on such worlds. But they argue that unless that life can adapt to rapid changes on such planets, it won’t last long — it’ll die off in less than a billion years. Surviving that early period may be “like trying to ride a wild bull,” they wrote: “Most life falls off.”

But life on Earth held on. Early single-celled organisms altered the climate enough to allow more complex forms of life to develop. And life adapted quickly enough to overcome impacts with comets and asteroids, the loss of water and other key compounds, and other unhealthy events.

If the researchers are right, then Earth is a rarity: a world where life altered the climate enough to keep itself going — a world worth a visit by a starship.


Script by Damond Benningfield

Get Premium Audio

Listen to today's episode of StarDate on the web the same day it airs in high-quality streaming audio without any extra ads or announcements. Choose a $8 one-month pass, or listen every day for a year for just $30.