reposted from: nationalgeographic.com
January 10, 2007—In a thousand years, astronomers predict, people on Earth will see the iconic "Pillars of Creation" get toppled by a supernova, the explosive death of a giant star.
The pillars are dense clouds of gas in the Eagle Nebula, a star nursery in the constellation Serpens, near Sagittarius. They were made famous by a dramatic 1995 Hubble Space Telescope image (inset).
The tricky part is that the forecast is based on evidence that the pillars were demolished by the supernova's shockwave about 6,000 years ago.
"[They] have been destroyed. I use the past tense because the nebula is 7,000 light-years away," said Nicholas Flagey, a French doctoral student working for NASA.
In other words, light from the nebula has taken 7,000 years to reach Earth, and everything we see is that much out of date.
This recent infrared image of the Eagle Nebula shows a bubble of hot, rapidly expanding material directly behind the pillars, Flagey reported on January 8 at a meeting of the American Astronomical Society in Seattle, Washington.
In the image, taken by NASA's Spitzer Space Telescope, a red mass of hot dust warmed by the supernova can be seen behind the ghostly green of the nebula. The pillars are directly in the shockwave's path.
"The pillars are not dense enough to resist" the blast, Flagey said.
The red ball can't simply be gas heated by nearby stars, he added, because only a supernova could generate that much energy.
But the blast isn't entirely bad news. Supernova shockwaves, astronomers believe, help to ignite new stars in the dust clouds that they reach.
—Richard A. Lovett
No comments:
Post a Comment