From the April 2008 issue

What is the theory of panspermia?

Fatima Fizbit, North Las Vegas, Nevada
By | Published: April 1, 2008 | Last updated on May 18, 2023
Earth
The panspermia hypothesis suggests life began on Earth when the “seeds” of life, already present in the universe, arrived here from space. How did these seeds, or microbes, get here? Proposed transport methods include meteorites, comets, and spacecraft.

Greek philosopher Anaxagoras wrote about the idea in the 5th century B.C. Since then, other scientists, including British astronomer Sir Frederick Hoyle (1915–2001), believed panspermia not only explained how life originated here, but also proposed the process continues to bring microbes or other life-forms to Earth. — Laura Layton, Associate Editor
The panspermia hypothesis suggests life began on Earth when the “seeds” of life, already present in the universe, arrived here from space.