Orion Planets
The Orion Nebula is a giant stellar nursery -- a cocoon of gas and dust that's given birth to thousands of stars, with many more still taking shape. But while the nebula is a nurturing environment for new stars, it may not be such a good place for new planets -- especially in the nebula's heart.
Planets are born from the material that's left over from the birth of a star -- broad disks of gas and dust. Over time, the dust grains begin to stick together to form larger bodies. These clumps may then sweep up some of the gas to grow even bigger.
But the center of the Orion Nebula is like a blowtorch. Strong winds and deadly radiation from several hot, massive stars buffet the stars around them, blowing away the leftover gas and dust -- leaving little to make planets.
Even so, the clumps of dust around some of the stars in the nebula are still growing. But they won't necessarily last for long. A few years ago, the star known as FU Orionis appeared to digest a big clump of planet-making material, causing the star to flare brightly. A similar fate may await the newly forming planets around other stars -- especially those that form close in: The thick dust and gas may slow these planetary embryos enough to force them to slam into their parent stars.
Look for the Orion Nebula in the southern sky this evening. It's a faint smudge of light just below the three bright stars that mark Orion's Belt.
More about Orion tomorrow.
Script by Damond Benningfield, Copyright 2009
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