Planet earth gets a twin

With almost matching densities, astronomers have recently discovered a planet with similarities to Earth. However, the twin-like planet is distinctively 2 000°C hotter.

Kepler-78b had a diameter just 20% larger than Earth’s. It has roughly the same density as Earth, making it most likely to consist of rock and iron.

The planet was discovered using data from Nasa’s Kepler space telescope, and two independent research teams then used ground-based telescopes to confirm and characterize Kepler-78b.

Astronomer David Latham of the Harvard-Smithsonian Center for Astrophysics (CfA), says Kepler-78b is a member of a new class of planets recently identified in data from Nasa’s Kepler spacecraft.

“This planet is a complete mystery,” he says. “We don’t know how it was formed or how it got to where it is today. What we do know is that it’s not going to last forever.”

Due to the scorching lava on Kepler-78b’s surface, the planet is uninhabitable.

Astronomers agree with Latham’s predictions that the planet will eventually vanish within three billion years. Gravitational forces will draw it even closer to its start, eventually ripping it apart.

Vincent Nettmann, resident astronomer at Maropeng, the official visitor centre for the Cradle of Humankind World Heritage Site, says that as the centre for the origins of humankind, this discovery has special significance for them. “It’s fascinating to know that a planet so similar to ours is out there.”

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