Earth’s Future in the Pegasus Constellation?

It may be some four to five billion years off, but scientists are still trying to determine how Earth will cope when the inevitable end of our sun arrives. As such, an international team of astronomers have announced the discovery of a planet orbiting a star that has a similar rotation to Earth’s. The exciting news for them though is that the star it is orbiting is nearing the end of its life.

Culminating in seven years worth of research, the announcement will be published in the September 13th edition of the journal Nature.

“V 391 Pegasi b,” – the planet in question – is orbiting its parent star, “V 391 Pegasi,” a faint star in the Pegasus constellation, which has undergone the primary stages of death after exhausting its supply of hydrogen fuel. A star will then expand enormously as a red giant, and expel its outer layers in an explosive helium flash. The fascinating discovery is that “V 391 Pegasi b,” has so far survived these stages.

“The exciting thing about finding a planet around this star is that it indicates that planetary systems can survive the giant phase and the helium flash of their parent star,” said Steve Kawaler, an Iowa State professor of physics and astronomy. “It bodes well for the survival of our own Earth in the distant future. Before V 391 Pegasi lost its outer regions at the helium flash, the planet orbited the star at about the same distance that the Earth orbits our sun.”

However, hope may not be all it’s cracked up to be, according to Kawaler. “We shouldn’t take too much heart in this – this planet is larger than Jupiter, so a smaller planet like the Earth could still be vulnerable.”
Kawaler helped coordinate observations during a 2003 run of the “Whole Earth Telescope”, which allows astronomers to take uninterrupted measurements of variable stars that change in brightness using a worldwide network of cooperating observatories.

Earth’s biggest challenge will come as our sun begins its growth phase, a natural stage of becoming a red giant. Many stars easily encompass their inner ring of planets as they grow, and astronomers believe that Mercury and Venus will inevitably disappear, whereas Mars will hopefully survive.

The question remains, will Earth disappear. As it is at the outer limit of such an expansion, astronomers are uncertain, but not hopeful. “…it appears more likely that the Earth will not survive the red giant expansion of the sun either, but it is not for sure,” said Roberto Silvotti from the INAF-Osservatorio Astronomico di Capodimonte in Naples, Italy.

Thankfully, we have a few years left before our move to Mars.

Posted by Josh Hill.

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