Fay forces closing of Kennedy Space Center
CAPE CANAVERAL, Fla., Aug. 19 (UPI) -- U.S. space agency officials closed the Kennedy Space Center Tuesday for 24 hours because of the threat posed by Tropical Storm Fay.
The National Aeronautics and Space Administration said Fay, which made landfall Tuesday morning along Florida's southwest coast, was forecast to produce heavy rainfall and possible tropical storm force winds over the Cape Canaveral area.
"While most of Kennedy's almost 15,000 employees will not be at work, the center will have a small group of emergency personnel, known as a "ride-out crew," who will stay at the center to provide real-time assessments of the storm situation," NASA said, noting there are about 200 people on the ride-out crew.
NASA officials said all three space shuttles were secured in hangers and their payload bay doors were closed to protect them from possible damage. Critical Hubble Space Telescope and International Space Station flight hardware were also protectively covered.
ESA corrects Rosetta spacecraft trajectory
PARIS, Aug. 19 (UPI) -- The European Space Agency says it has successfully corrected its Rosetta spacecraft's trajectory, optimizing its fly-by next month of the asteroid Steins.
The trajectory correction Friday used data from the ESA's first optical tracking of an asteroid target, with the spacecraft's cameras used to calculate the asteroid's location.
Rosetta's first major correction maneuver in the approach phase took place while the spacecraft was approximately 10.5 million miles from Steins. The spacecraft's thrusters burned for approximately 2 minutes, correcting its Sept. 5 fly-by trajectory.
"The closer we get to Steins, the more accurate our knowledge of the asteroid's position relative to Rosetta will be," said Trevor Morley, leader of the Rosetta Flight Dynamics Orbit team. "Thanks to Rosetta's cameras, we will obtain increasingly precise measurements that will allow us to adjust again, if necessary, Rosetta's orbit for an optimal asteroid encounter."
Evidence of century-long droughts found
ATHENS, Ohio, Aug. 19 (UPI) -- A stalagmite discovered in a U.S. cave has yielded detailed geological data on 7,000 years of eastern North America climate cycles.
The Ohio University-led study confirms that during periods when the Earth received less solar radiation a series of century-long droughts occurred.
Researchers led by Assistant Professor Gregory Springer said the stalagmite preserved climate conditions over periods as brief as a few years. The scientists said they found evidence of at least seven major droughts during the Holocene era.
The stalagmites from West Virginia's Buckeye Creek Cave provide an excellent record of climate cycles because that state is affected by jet streams and moisture from both the Gulf of Mexico and the Pacific Ocean, Springer said.
Other studies have gleaned climatic data from lakes, but fish and other animals tend to churn the sediment, muddying the geological record, said Assistant Professor Harold Rowe of the University of Texas-Arlington, a co-author of the study.
"(The caves) haven't been disturbed by anything," said Rowe. "We can see what happened on the scale of a few decades. In lakes of the Appalachian region, you're looking more at the scale of a millennium."
The research appears in the journal Geophysical Research Letters.
Old bacteria relied on arsenic, not water
WASHINGTON, Aug. 19 (UPI) -- U.S. scientists say they have discovered ancient bacteria that relied on arsenic, rather than water, to grow during photosynthesis.
The discovery, which the scientists said likely dates to a few billion years ago, came in research funded by the National Aeronautics and Space Administration's Exobiology Program and the U.S. Geological Survey.
The finding is said to add an important dimension to the arsenic cycle "and highlights a previously unsuspected process that may have been essential for establishing the arsenic cycle on the ancient Earth," the USGS said. The arsenic cycle occurs when enzymes trigger microorganisms to convert inorganic arsenic to organic arsenicals.
The discovery came during a study of two small hot spring-fed ponds on the southeastern shore of Paoha Island in Mono Lake, Calif.
The research that included scientists from Duquesne University, the University of Georgia and Southern Illinois University appears in the journal Science.
