August 21, 2012 12:11 pm
Earth Will Die a Hot Horrible Death when the Sun Expands and Swallows Us, and Now We Know What That Looks Like
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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While it’s a great way to get people’s attention so that they will read this article, we do not know for certain whether Earth will suffer the same fate as the planet mentioned in this article. There’s some debate amongst scientists who also believe that the Earth may be pushed further outward in it’s orbit along with the outer planets. We will never know for certain. What is more certain is that the earth will be rendered uninhabitable long before the Sun engulfs it.
Comment by Neil — August 21, 2012 @ 11:23 pm
Hi Neil,
Thanks for your comments on this. I did try to address the ongoing debate over the issue which you bring up by pointing people to David Appell’s great story on the issue from a few years back. However, it does seem to be the dominant view that an expanding Sun wouldn’t be particularly kind to our little blue sphere.
Comment by Colin Schultz — August 22, 2012 @ 12:18 am
I didn’t realize that the sun was in an ever expanding mode that will eventually reach it’s zenith. I always thought that there would be a “sudden” flare-up. (Sudden as in a couple hundred or thousand years).
Sorta like a supernova only not having enough mass it doesn’t blow itself apart, just flares then dies down to a white dwarf or whatever.
Thanks for the article Colin.
Comment by Mike — August 22, 2012 @ 3:09 am
Then again our glass may be half full? Are we not just in the right place in our solar system to cause the outward pulsing gravity (flair-ups)of a dying red sun to nudge us out and into a further orbit away from the ever expanding sun? Or is that just science mumbo jumbo?
Comment by Norman — August 22, 2012 @ 4:27 pm