Saturday, 26 September 2009

Johnald's Fantastical Daily Link Splurge

Johnald's Fantastical Daily Link Splurge


Reader Photo Gallery: Awesome DIY Astronomy

Posted: 25 Sep 2009 03:30 PM PDT

aa_pelicannebula

Wired Science has some great amateur astronomers among our readers and followers. Our first reader-contributed space photo was an eerie glowing space bubble. We asked on Twitter and in a post for more of your photos of space, and we got some beautiful images in return. Thanks!

Above: Elias Jordan sent us this superb shot of the Pelican Nebula that he took in June with an astronomical camera (SBIG STL11000M) and a telescope (Takahashi FRC 300). The exposure time was 114 minutes. How awesome is it that someone can get an image this nice of something 2,000 light years away, basically from a backyard in New Mexico?

Below: Arran Hill shared this terrific image of the Pacman Nebula, more officially known as NGC 281. This star-forming region 10,000 light years away got its nickname from its overall shape, which resembles an open-mouthed Pacman. This image required 69 15-minute exposures, for a total of more than 17 hours divided among three different filters. Sulfur gas appears reddish, hydrogen is green and oxygen is blue.

"This gives a false color," Hill wrote in an e-mail. "But by using it, more delicate and subtle structure is revealed in the image."

If you've got some super space shots you'd like to see featured on Wired Science, let us know by e-mail or on Twitter @wiredscience.

See more images by all three of our reader astrophotographers on the next page.

aa_pacman1

More images on the next page.

Four-Winged Fossil Bridges Bird-Dinosaur Gap

Posted: 25 Sep 2009 12:10 PM PDT

anchiornis-artist

BRISTOL, England — A newly described, profusely feathered dinosaur may give lift to scientists' understanding of bird and flight evolution, researchers report. The lithe creature, which stood about 28 centimeters tall at the hip, is the oldest known to have sported feathers and is estimated to be between 1 million and 11 million years older than Archaeopteryx, the first known bird.

sciencenewsSeveral fossils of the creature, which has been dubbed Anchiornis huxleyi, have been unearthed in northeastern China, Xing Xu reported September 25 at the annual meeting of the Society of Vertebrate Paleontology. The strata that contained those feathered fossils were laid down as sediments between 151 million and 161 million years ago, he and his colleagues note online September 24 in Nature.

Two types of feather adorn the creature, said Xu, of the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing. One kind, commonly referred to as "dino-fuzz," resembles a frayed bundle of filaments. The other type, similar in overall structure to the feathers of modern-day birds, consists of small filaments that branch from a larger shaft-like filament.

birdcartoonThe dino-fuzz decorates the creature's head and neck. About two dozen of the shafted feathers adorn each forelimb, and a similar number embellish each lower leg and foot, the researchers report. Unlike most feathered dinosaurs described previously, which have the longest forelimb feathers near the tip of the limb,
Anchiornis' longest forelimb feathers are on the wrist, Xu said. Feathers on the legs and feet appear to have overlapped each other, creating aerodynamic surfaces that would have, in essence, given Anchiornis a wing on each of its four limbs. A similar configuration has been seen in other feathered dinosaurs, including Microraptor (SN: 1/27/07, p. 53) and Archaeopteryx (SN: 9/23/06, p. 197).

With so many species with this arrangement, the four-winged configuration must have been an important phase in the evolutionary transition from dinosaurs to birds, says James M. Clark, a vertebrate paleontologist at George Washington University in Washington, D.C.

Larry D. Martin, a paleontologist at the University of Kansas in Lawrence, agrees. The profuse plumage on Anchiornis' feet, he notes, also suggests that the creature was a tree dweller, bolstering the notion that flight developed from the trees down, not from the ground up. "No dinosaur could walk well with feathers on its feet like that," he adds.

Many scientists scoff at the suggestion that the filamentary structures found on some dinosaurs, especially those unearthed in China in recent years, represent nascent feathers. But those creatures lived many millions of years after Archaeopteryx, which had feathers indistinguishable from those on modern-day birds. The new find is important because it undoubtedly includes the oldest known feathers on any creature, says Mike Benton, a vertebrate paleontologist at the University of Bristol in England and cochair of the Society of Vertebrate Paleontology meeting.

"These exceptional fossils provide us with evidence that has been missing until now," Xu said. "Now it all fits neatly into place, and we have tied up some of the loose ends."

Images: 1) Zhao Chuang/Xing Lida. 2) Xing Xu et al.

See Also:

No comments:

Post a Comment