The discovery of a planet similar to Venus around a star in the neighborhood of the solar system raises hopes that astronomers may someday unlock the secret to why life appeared on Earth.
The discovery of a planet similar to Venus around a star in the neighborhood of the solar system raises hopes that astronomers may someday unlock the secret to why life appeared on Earth.
The study of life in the universe is difficult because we have only one example of a planet where life has been confirmed: Earth. It is difficult to say which characteristics of Earth are required for life to appear, and which are irrelevant. Until we find an «Earth twin» where the conditions for life also appeared, the best astronomers can do is study «evil twins,» planets with initial conditions similar to Earth that turned out very differently, with environments unsuitable for life.
In the solar system, Venus and Mars provide two examples of lifeless «evil twins.» But with only two examples, there is still much uncertainty about how stringent or lax the conditions for life may be.
