A new model suggests that ten percent of stars in the milk strain offer the conditions for complex life
The Astronom Guillermo Gonzales pruddled the term of the "Galactic inhabitability zone" (GHZ) . However, his data was not so predictable as those of Charles Lineweaver and colleagues who introduce a future version in Science: In our milk strain, a ring-shaped region takes a rough one (cf). 30 billion earths in our milk strain?To). What has it with this model of evolution?
Ultimately, it is about the preaching of a dominant star, enough so genant elements to make terrestrial planets, sufficient time for biological development and an environment that is free from the destruction of life-limiting Supernovas. Thus, the authors describe a galaxy whose stars have a proper elements for the emergence of an earth-same planet
However, these predictions are only to be examined in a few decades if the scientists know more about the planner outside of our solar system. The GHz, the "Galactic Habitable Zone", is a ring-shaped region that lies in the galactic disk and the heavy elements require how they are required for the formation of terrestrial tarpaulin and includes biological education complex multi-cellular life.
The simulation of the galaxy follows in two surprising periods, the formation of halo and disk. Although a delay between the formation of the shell formation and the dun disk formation, these advances are handled. Furthermore, the researchers in their model observe the formation of heavy metals, so everything auber hydrogen and helium, as well as the exchange between the stars and the gas. With too little metal, it is impossible for earthly plans to form, with too much metal gigantic planets that destroy the earthy structures.
The galactic living room is in a spiral galaxy a ring-shaped region located in the galactic disk (pictures: Yeshe Fenner / Space Telescope Institute)
The equation for GHz is thus: PGHZ = SFR X PMETALS X PEVOL X PSN, where SFR symbolizes the star formation, Pmetals the metal formation, PEVOL the evolutionary time and PSN the life-staring Supernova explosions.
This equation lets itself after the four coarse nobles and thus allows time to calculate the statistically possible on the acceptance of the relevance on Earth. The death of massive stars, thought is the eight times the sun, supernovas. Over the radiations (cosmic, gamma, ray beams) and the waves, you will destroy earth-tooth planets. On the other hand, sufficient time will be necessary on the planet to develop and form biological life.
Zeitsequence of a galaxy of our milk strain with the formation and expansion of a "Galactic Habitable Zone" (green). In the Fruhen Phase (supported image) there are not enough heavy elements to produce the terrestrial planets under the influence of neighboring Supernovae (red). The moment to gain in importance in the heavy elements, terrestrial planets are increasingly formed and a habitable zone is created and is expanded
All data taken together provide a surprising insight: 8 million years and 25.000 light years removed from the galactic center – quite like the removal of the sun from our planet. This zone has slowly released from the galactic center. Furthermore, more than three quarters of the star age than the earth, namely more than a billion years. "If you want to know if the extraterrestrial intelligence is developing, this is a cute creation. One billion years is a long, long time," explains Charles Lineweaver.
Other astronomers see that differently. Virginia Trimble from the University of California, which moved in 1997 the galactic habitability in effect, notes: "Quantitative statements are not better until you can be sure that the numbers are genuine. I think the authors give the environment too much attention. Because if a complex life takes twice as long as on earth, then the old stars who are closed to the center have more influence – regardless of the Supernovae."
Nevertheless, Charles Lineweaver sees good reason to demand the debate: "When it comes to the development of life, the astronomers twitching twitching. It’s just a taboo. I could encourage the astrobiological community to pursue this question."