Publication Date:
2004-01-06
Description:
We modeled the evolution of the Milky Way Galaxy 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.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lineweaver, Charles H -- Fenner, Yeshe -- Gibson, Brad K -- New York, N.Y. -- Science. 2004 Jan 2;303(5654):59-62.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Astrophysics, University of New South Wales (NSW), Sydney, NSW 2052, Australia. charley@bat.phys.unsw.edu.au〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/14704421" target="_blank"〉PubMed〈/a〉
Keywords:
Astronomical Phenomena
;
*Astronomy
;
Computer Simulation
;
Evolution, Chemical
;
Evolution, Planetary
;
*Exobiology
;
Extraterrestrial Environment
;
Models, Theoretical
;
Probability
;
Time
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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