A carbon-rich black layer, dating to {approx}12.9 ka, has been previously identified at {approx}50 Clovis-age sites across North America and appears contemporaneous with the abrupt onset of Younger Dryas (YD) cooling. The in situ bones of extinct Pleistocene megafauna, along with Clovis tool assemblages, occur below this black layer but not within or above it. Causes for the extinctions, YD cooling, and termination of Clovis culture have long been controversial. In this paper, we provide evidence for an extraterrestrial (ET) impact event at {cong}12.9 ka, which we hypothesize caused abrupt environmental changes that contributed to YD cooling, major ecological reorganization, broad-scale extinctions, and rapid human behavioral shifts at the end of the Clovis Period. Clovis-age sites in North American are overlain by a thin, discrete layer with varying peak abundances of (i) magnetic grains with iridium, (ii) magnetic microspherules, (iii) charcoal, (iv) soot, (v) carbon spherules, (vi) glass-like carbon containing nanodiamonds, and (vii) fullerenes with ET helium, all of which are evidence for an ET impact and associated biomass burning at {approx}12.9 ka. This layer also extends throughout at least 15 Carolina Bays, which are unique, elliptical depressions, oriented to the northwest across the Atlantic Coastal Plain. We propose that one or more large, low-density ET objects exploded over northern North America, partially destabilizing the Laurentide Ice Sheet and triggering YD cooling. The shock wave, thermal pulse, and event-related environmental effects (e.g., extensive biomass burning and food limitations) contributed to end-Pleistocene megafaunal extinctions and adaptive shifts among PaleoAmericans in North America.

A modified plastic material greatly improves the ability to separate global warming-linked carbon dioxide from natural gas as the gas is prepared for use, according to engineers at The University of Texas at Austin who have analyzed the new plastic's performance.

©Erin McCarley

Freeman holds a sample of the new membrane material found to greatly improve the ability to separate global warming-linked carbon dioxide from natural gas as the gas is prepared for use. The new membrane's capabilities will be reported in the Oct. 12 issue of Science.

Japan's robotics industry is expected to show robust growth and remain the world leader thanks to growing exports to emerging economies, an industry group said Thursday.

©Unknown

University of Minnesota researchers contributed to a national effort to sequence the genome of an ancient, one-celled organism that will help advance research in a broad range of areas, from biofuels to restoring the environment to understanding a variety of human diseases.

©Unknown

Chlamydomonas reinhardtii, known affectionately as "Chlamy," is an ancestor of plants and animals that retains characteristics of both.

Gene targeting, a pervasive technology that allows scientists to isolate, modify and recombine mouse DNA, got its name in lights this morning when its three creators won the 2007 Nobel Prize in medicine.

The University of Maastricht in the Netherlands is awarding a doctorate to a researcher who wrote a paper on marriages between humans and robots.

David Levy, a British artificial intelligence researcher at the college, wrote in his thesis, "Intimate Relationships with Artificial Partners," that trends in robotics and shifting attitudes on marriage are likely to result in sophisticated robots that will eventually be seen as suitable marriage partners.

French archaeologists have discovered an 11,000-year-old wall painting underground in northern Syria which they believe is the oldest in the world.

©REUTERS/Handout

A view of a painting uncovered at Djade al-Mughara Neolihic site, northeast of the Syrian city of Aleppo, in this September 2007 handout photo.

STOCKHOLM, Sweden -- Gerhard Ertl of Germany won the 2007 Nobel Prize in chemistry on Wednesday for studies of chemical reactions on solid surfaces, which are key to understanding questions like why the ozone layer is thinning.

©Unknown

An artist's impression of the view of the Earth from the Moon if we could see in X-rays. The Earth is surrounded by an X-ray glow caused by particles from the Sun colliding with the gas trapped within the Earth's magnetic shield.

Scientists from the University of Leicester have taken an important first step in developing an innovative telescope which could one day be deployed on the Moon. The telescope is called MagEX, which stands for "Magnetosheath Explorer in X-rays" and is an international collaboration between scientists from the United States, the Czech Republic, and the University of Leicester. MagEX will study the magnetosheath, the magnetic "shield" that protects the Earth from the solar wind - the high energy particles that continuously flow out from the Sun. Without this shield, life on Earth as we know it could not exist.

Recent observations from NASA and Japanese X-ray observatories have helped clarify one of the long-standing mysteries in astronomy -- the origin of cosmic rays. Outer space is a vast shooting gallery of cosmic rays. Discovered in 1912, cosmic rays are not actually rays at all; they are subatomic particles and ions (such as protons and electrons) that zip through space in all directions at near-light speed, with energies tens of thousands of times greater than particles produced in Earth's largest particle accelerators.

©JAXA/ Takaaki Tanaka/HESS

This image from Japan's Suzaku X-ray observatory shows RXJ1713.7-3946. This supernova remnant is the gaseous remnant of a massive star that exploded. The remnant is about 1,600 years old. The contour lines show where gamma-ray intensity is highest, as measured by the High Energy Stereoscopic System (HESS) in Namibia.