Where do the odds lie?

If you had some money to bet on the existence of life and intelligence elsewhere, what would you bet on?

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Earth’s habitable window began 4.2 billion years ago after a young Earth collided with a Mars-sized body, dubbed Theia, 300 million years prior. Habitability only began when the oceans settled and the atmosphere returned to stability after the event.

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The strongest evidence of ancient life, derived from microfossils, dates back to 3.5 billion years ago. The more disputed evidence, derived from carbon-13depleted zircon sources, says life could have been around as early as 3.9 billion years ago.

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It is hard to confine the inception of intelligent life and humanity’s arrival. In the case of this study, Kipping states that the start of intelligence should date back to Homo sapiens emerging within the last half a million years, which is negligible when considering the grander timeframe.

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We are currently living in the twilight years of Earth’s habitable window, with less than a billion years left on the clock before the Sun heats up, starts pulling carbon dioxide out from rocks and making the air toxic and unbreathable.