Unexpected planet


A planet circles a star 560 light-years away in the constellation Draco. It shouldn’t be there, according to what used to pass for conventional wisdom.

The planet is twice the size of Earth, with 17 times its mass. Astronomers say it is rocky, has an atmosphere, and has water despite its high surface temperature.

The 11-billion-year-old planet is too hot to harbor life as we know it. If it were part of our solar system, we would expect it to conform to the model provided by planetary giants such as Jupiter and Saturn.

Once a planet passes a certain size, it is supposed to be a large swirling, ball of hydrogen and other gasses, according to the old model. This planet was formed 3 billion years after the Big Bang, supposedly too early for planets of its size and density to have formed.

To say our previous theories of planetary formation need drastic updates is an understatement, but that’s the beauty of scientific inquiry. It forces us to reassess our comfortable assumptions.

Who says there’s nothing new under the sun? Sometimes a planet that defies all expectations is circling the sun.