Earth-like planet models built in hunt for alien life

In their hunt for alien life, astronomers have built an array of Earth-like planet models that examine how ultraviolet radiation from other planets' nearby suns may affect those world.

Researcher Lisa Kaltenegger said that depending on the intensity, ultraviolet radiation can be both useful and harmful to the origin of life and added that they are trying to ascertain how much radiation other young Earths would get and what that could mean for the possibility for life.

Lead author Sarah Rugheimer said that they are going to see all kinds of planets in all kinds of stages in their own evolution, but they wanted to take four kinds of epochs from Earth history, as samples of what they might see. With the next generation of missions, they expect to observe a wide diversity of extrasolar planets.

The researchers noted that for all epochs after the rise of oxygen the hottest and coolest stars have less biologically effective radiation. For the hottest stars, this is due to increased ozone shielding from higher UV environments, and for the coolest stars this is due to less absolute UV flux.

Rugheimer explained that astrobiology draws researchers across disciplines and noted that this work provides a link from the astrophysical conditions they expect to find on other planets to the origin-of-life experiments happening on here on Earth.

The study is published in Astrophysical Journal.