![]() "We are realizing that most of the Jupiter-like planets. "A trend is now being stamped on these discoveries that we thought, frankly, would go away," said Geoffrey Marcy of San Francisco State University at a recent meeting of the American Astronomical Society in Austin. And yet something has halted their gravitational death spiral before it carried them "down the drain" to destruction.Īll of the remaining nine extrasolar planets – those maintaining average distances of at least 19 million miles from their stars (about one-fifth Earth's distance from the sun) – follow "eccentric" (egg-shaped) orbits – killer orbits. Physical laws seem to dictate that they could not have formed that close and so must have migrated inward early in the system's history (wreaking havoc on any other fledgling worlds in their path). The closest of these "hot Jupiters" whips around its star at such scorching proximity that its "year" – one complete circuit – lasts just 3.3 days. But eight of them are bound in tight, circular orbits that skim astoundingly close to their stars. It is not surprising that the hunters would find the largest, most obvious planets first. The growing population of known extrasolar planets so far offers shocking contrasts with our own home solar system, defying theories based on that familiar model and challenging scientists to cobble together new ones.Īll 17 extrasolar bodies appear to be roughly as massive as the largest planet in our solar system – the giant gas ball Jupiter. The tally is getting high enough to show statistical patterns that, scientists say, may be telling them something new about how nature forms and destroys planets, and just how fragile the prospects for life-harboring worlds like Earth may be. Such questions arise from the extraordinary burst of discovery that began in 1995, in which astronomers say they have found a total of 17 worlds orbiting sun-like stars outside the solar system – and counting. Is Earth a "lucky" planet, dwelling in a rare gem of a solar system that somehow escaped the gravitational wrecking balls that have knocked other planetary systems cockeyed? Or is the sun's realm fairly typical in its symmetry and orderliness? Jumping Jupiter! Is Our Solar System a Rarity?Īn artist rendition, released by NASA, of the dark side of Jupiter. : Jumping Jupiter! Is Our Solar System a Rarity?
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |