The galactic habitable zone and the age distribution of complex life in the Milky Way

Author(s)

Lineweaver, Charles H.; Fenner, Yeshe; Gibson, Brad K.

Abstract

We modeled the evolution of the Milky Way to trace the distribution in space and time of four prerequisites for complex life: the presence of a host star, enough heavy elements to form terrestrial planets, sufficient time for biological evolution and an environment free of life-extinguishing supernovae. We identified the Galactic habitable zone (GHZ) as an annular region between 7 and 9 kiloparsecs from the Galactic center that widens with time and is composed of stars that formed between 8 and 4 billion years ago. This GHZ yields an age distribution for the complex life that may inhabit our Galaxy. We found that 75% of the stars in the GHZ are older than the Sun.

Publication year

2004

Publication type

Journal article

Source

Science, Vol. 303, no. 5654 (Jan 2004), pp. 59-62

ISSN

0036-8075

Publisher

American Association for the Advancement of Science

Copyright

Copyright © 2004 American Association for the Advancement of Science.

Details