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Stellar Destruction Made Sol's Future Bright
Washington DC (SPX) - May 11, 2005 Earth's early existence was likely a time of uncertain survival. Forming in a hostile environment, the Earth and neighboring developing planets had to compete for materials and steer clear of the ravenous Sun. But scientists with NASA's Chandra X-ray Observatory believe help in forming the Solar System may have come from a menacing and unlikely source: the Sun's own X-ray super-flares. "Big X-ray flares might lead to planetary systems like ours," said Eric Feigelson, a principal investigator for the science team using Chandra to study the phenomena. One way to gauge the Sun's influence is to blast to the past by looking at younger stars in the constellation Orion. "We don't have a time machine to see how the young Sun behaved, but the next best thing is to observe Sun-like stars in Orion," said Scott Wolk of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. "We are getting a unique look at stars between one and 10 million years old � a time when planets form." Young stars are surrounded by a debris field called a "planet-forming disk." As planets take shape within the disk, wakes form that push them toward and away from the star. The shove toward the star tends to be strongest, causing the planets to move perilously closer to it. The deciding factor appears to be the size of the star's X-ray flares. "Stars with smaller flares...might end up with 'hot jupiters,' or simply with no giant planets because they plummet into the star," Feigelson said. Hot jupiters are scorched, oversized planets orbiting near a star. Chandra scientists believe the threat diminishes when the disk is struck by large X-ray flares. The lashing electrically charges the disk and combines with other factors to produce incredible turbulence. "Although these flares may be creating havoc in the disks, they ultimately could do more good than harm," said Feigelson. "These flares may be acting like a planetary protection program." Choppy stellar waters jostle the budding planets. The buffeting forces the planets to haphazardly waddle around the disk in a "random walk" and avoid falling into the star. Scientists also suspect this walkabout allows planets to safely wander the disk, collecting more material and grow larger. The end result is the increased possibility young planets can mature into something like those in our Solar System. In times of danger, it's good to separate friend from foe. In the case of the Earth and Solar System, the Sun appears to have been both. The burning star not only served as a planet's biggest threat to survival, but also its greatest promise of a future. Community Email This Article Comment On This Article Related Links Orion at Harvard Chandra at Harvard SpaceDaily Search SpaceDaily Subscribe To SpaceDaily Express Lands Beyond Beyond - extra solar planets - news and science Life Beyond Earth
Study Highlights Role Of Hit-And-Run Collisions In Planet Formation
Santa Cruz CA (SPX) Jan 12, 2006Hit-and-run collisions between embryonic planets during a critical period in the early history of the Solar System may account for some previously unexplained properties of planets, asteroids, and meteorites, according to researchers at the University of California, Santa Cruz, who describe their findings in a paper to appear in the January 12 issue of the journal Nature. |
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