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Earth Will Die a Hot Horrible Death when the Sun Expands and Swallows Us, and Now We Know What That Looks Like

Astronomers caught a red giant star swallowing one of its planets, a vision of Earth's own potential fate

BD+48 740 is just a bit bigger than Pollux, seen here dwarfing our own Sun. Photo: Omnidoom 999

Spend enough time meditating in the cave of dreams and you might just be gifted visions of the future. Or, for the same effect, peer through a telescope for a little while. A team led by astronomer Alex Wolszczan caught a glimpse of Earth’s fate, nay, destiny, in the red-giant star BD+48 740.

As reported by Universe Today, the astronomers saw in BD+48 740 signs that it had recently enveloped and consumed one of its planets. This is a portend of Earth’s own impending doom, says lead researcher Wolszczan in a release issued by Penn State.

A similar fate may await the inner planets in our solar system, when the Sun becomes a red giant and expands all the way out to Earth’s orbit some five-billion years from now.

They rest their case on unusually high lithium concentrations that they found when they were analyzing the star’s chemical composition, and on the wonky orbit of the red giant’s other planet. One of the researchers, Eva Villaver, says,

The highly elongated orbit of the massive planet we discovered around this lithium-polluted red-giant star is exactly the kind of evidence that would point to the star’s recent destruction of its now-missing planet.

Though there is some debate over whether the Sun’s expansion will actually lead to the end of the world, says David Appell in Scientific American, the common view of how the scenario looks is a little like this:

The sun is slowly expanding and brightening, and over the next few billion years it will eventually desiccate Earth, leaving it hot, brown and uninhabitable. About 7.6 billion years from now, the sun will reach its maximum size as a red giant: its surface will extend beyond Earth’s orbit today by 20 percent and will shine 3,000 times brighter. In its final stage, the sun will collapse into a white dwarf.

When the Sun’s surface expands beyond Earth’s orbit, say goodbye to plagiarius terra.

More from Smithsonian.com:
The Sun is Just 0.0007% Away From Being a Perfect Sphere
Brilliant Space Photos From Chandra and Spitzer
What if All 2,299 Exoplanets Orbited One Star?

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About Colin Schultz
Colin Schultz

Colin Schultz is a freelance science writer and editor based in Toronto, Canada. He blogs for Smart News and contributes to the American Geophysical Union. He has a B.Sc. in physical science and philosophy, and a M.A. in journalism.

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