Why haven’t we found aliens yet? [2016/02/04 10:01]

If the universe is full of the building blocks of life, why haven’t we found any? Because all the aliens are extinct, some scientists claim.

In a research paper published in the journal Astrobiology, Aditya Chopra and Charley Lineweaver from the Australian National University propose that most life would become extinct before it gets very far along the evolutionary process at all.

“The universe is probably filled with habitable planets, so many scientists think it should be teeming with aliens,” said Chopra. “Early life is fragile, so we believe it rarely evolves quickly enough to survive. Most early planetary environments are unstable.”

The hypothesis is that, while many planets may have good conditions for the emergence of life, at some point they become unsustainable. For instance, Venus, Earth and Mars may all have had similar conditions 4 billion years ago, when microbial life began to emerge on Earth.

Venus eventually grew too hot to sustain life, and Mars lost its atmosphere and water. Any life that had emerged would have failed to adapt to the rapid changes and become extinct.

Evidence shows that life on Earth was able to successfully emerge because life itself was making the planet habitable.

To date, scientists have located some 1,039 confirmed candidate planets, those that meet the basic conditions for supporting life. However, life has yet to be observed on any of these planets.
출처: 주니어 영자신문 주니어헤럴드(junior.heraldm.com)