Ancient planets are almost as old as the universe

New Scientist reports: The Old Ones were already ancient when the Earth was born. Five small planets orbit an 11.2 billion-year-old star, making them about 80 per cent as old as the universe itself. That means our galaxy started building rocky planets earlier than we thought.

“Now that we know that these planets can be twice as old as Earth, this opens the possibility for the existence of ancient life in the galaxy,” says Tiago Campante at the University of Birmingham in the UK.

NASA’s Kepler space telescope spotted the planets around an orange dwarf star called Kepler 444, which is 117 light years away and about 25 per cent smaller than the sun.

Orange dwarfs are considered good candidates for hosting alien life because they can stay stable for up to 30 billion years, compared to the sun’s 10 billion years, the time it takes these stars to consume all their hydrogen. For context, the universe is currently 13.8 billion years old.

Since, as far as we know, life begins by chance, older planets would have had more time to allow life to get going and evolve. But it was unclear whether planets around such an old star could be rocky – life would have a harder time on gassy planets without a solid surface. [Continue reading…]

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