Discoveries
Rutgers research that made the news this summer
Archived article from Oct 8, 1999
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The researchers found that not only were the hominids skilled at making their tools, they cleverly selected the right rocks, or cobbles, and understood where to start chipping the natural surfaces, which weren't always easy to work with, Feibel said. They also were able to maintain the proper flaking angles and reshape the core when necessary, skills that are considered fairly sophisticated.
-- Sandra Lanman
The moon's surface in miniature Two Rutgers physicists have performed the first laboratory studies to identify how highly volatile sodium in the moon's thin atmosphere is constantly replenished.
Research Associate Boris Yakshinskiy and Professor Theodore E. Madey, both of the Laboratory for Surface Modification at the department of physics and astronomy, Faculty of Arts and Sciences-New Brunswick, announced their findings in the Aug. 12 issue of the journal Nature.
The relatively thin atmosphere of the moon has been shown to contain measurable amounts of atomic sodium and potassium vapor. These atoms, however, remain in the atmosphere for only a few hours and must constantly be resupplied. Until now, scientists were unable to explain how this happened.
"Several mechanisms have been proposed to explain the resupply of atmospheric components from the lunar surface," said Madey. "Scientists have considered the effects of the solar wind (a loosely packed stream of particle radiation from the sun), micrometeorite impacts, release of elements caused by surface heating and release stimulated by the effects of light, but there was little data to support any one explanation and no general agreement about which processes are the most important."
To test various hypotheses, the physicists created laboratory simulations of the lunar surface and then demonstrated how the resupply of sodium to the lunar atmosphere from the surface occurs.
"We simply place a sample of the surface we intend to investigate in a good vacuum, we start throwing photons, electrons and ions at it, and then we look at what comes back from the surface and how," said Yakshinskiy, describing the use of highly sophisticated ultra-high vacuum apparatus, X-ray photoelectron spectroscopy, photon-stimulated desorption, temperature-programmed desorption and low-energy ion scattering in laboratory analysis.
Based on their experimental results, Yakshinskiy and Madey conclude that the electron flux or flow from the solar wind is too small to expel sodium from the lunar surface, "but the solar photon flux (the light itself) is more than sufficient. These measurements provide strong scientific support and rationale for the arguments ... that a photon-stimulated desorption (replenishment) process plays a major role in production of the lunar sodium atmosphere."
Some observable short-term, local sodium concentrations may also be attributed, they believe, to associated meteor showers.
"As we move out beyond the confines of our home planet, we must look to new scientific approaches to deal with the questions posed in this new era of planetary exploration," said Madey. "The study of surface modification is one such approach, already providing some of the answers we seek and helping us to understand the environments we will encounter on our solar system neighbors."
-- Joseph Blumberg
On the trail of a meteoroid Some 50,000 years ago, an object weighing approximately 60,000 tons and 100 feet in diameter explosively struck the desert near Winslow, Ariz., blasting out Meteor Crater. Approximately 4,000 feet wide and 570 feet deep, the crater was the first on Earth to be identified as having been created by a meteoroid.
By studying the remains of the object, known as the Canyon Diablo impactor, researchers can now describe how the character of the meteoroid changed as it traversed Earth's atmosphere and crashed into its surface, establish how the remaining fragments were formed, and determine where within the body of the meteoroid the fragments originated.
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