WASHINGTON, Jan. 30 (UPI) -- The U.S. space agency said its Messenger spacecraft showed that the planet Mercury appears to be surprisingly different from Earth's moon.
The National Aeronautics and Space Administration said that after a journey of more than 2 billion miles and 3 1/2 years, the Jan. 14 flyby of Mercury produced an entirely new look at the planet once thought to have characteristics similar to those of Earth's moon.
The spacecraft collected more than 1,200 images of the planet and made other scientific observations, including the first up-close measurements of Mercury since the Mariner 10 spacecraft's third flyby March 16, 1975.
Scientists said the images obtained by Messenger show Mercury has huge cliffs with structures snaking hundreds of miles across the planet's face. The images also revealed impact craters that appear very different from lunar craters.
"We should keep this treasure trove of data in perspective," cautioned project scientist Ralph McNutt. "With two flybys to come and an intensive orbital mission to follow, we are just getting started to go where no one has been before."
Potential new asthma treatment proposed
NEW YORK, Jan. 30 (UPI) -- U.S. scientists have found an enzyme released by mast cells in the lungs appears to play a key role in airway constrictions associated with asthma.
Weill Cornell Medical College medical researchers discovered that during an immune response, mast cells release the enzyme -- called renin -- that produces angiotensin, a potent constrictor of the smooth muscle that lines airways.
Weill Cornell scientists, in 2005, discovered mast cells in the heart released renin locally, triggering angiotensin production. "Now, we've expanded those findings to the lungs, where similar mechanisms appear to work locally to help trigger constriction in the airway," said study co-author Professor Roberto Levi.
Levi's co-author, Associate Professor Randi Silver, added: "In the heart and now the lungs, this localized production of renin appears to have a profound effect on nearby tissues, More study is needed, of course, but our finding suggests that drugs that target renin might prove effective agents in dampening asthma or other respiratory diseases."
The research that included Racha Estephan, Nathan O'Connor, Maria Thadani-Mulero and Mariselis Salazar-Rodriguez appears in the online edition of the Proceedings of the National Academy of Sciences.
Asteroid makes close approach to Earth
PASADENA, Calif., Jan. 30 (UPI) -- The U.S. space agency said Asteroid 2007 TU24 confirmed astronomers' predictions, making its closest approach to Earth at 3:33 a.m. EST Tuesday.
At its closest point, the asteroid was 344,370 miles from Earth, or roughly 1.4 times the distance between the moon and Earth, the National Aeronautics and Space Administration said.
Scientists at the NASA's Jet Propulsion Laboratory in Pasadena, Calif., had tracked the asteroid, which was about 660 yards long, in advance and determined there was no possibility of a collision with Earth.
But JPL scientists said the event provided a bonanza of information for scientists, who will scrutinize images and data they gathered in hopes of learning more about near-Earth asteroids.
More observations are planned through early next month using the Arecibo Observatory in Puerto Rico as the asteroid moves farther from Earth.
Brain signals governing exploration found
LYON, France, Jan. 30 (UPI) -- French scientists have identified an area of the monkey brain that might be linked with addiction and mental illness in humans.
University of Lyon researchers presented monkeys with a task while recording electrical activity in neurons of the anterior cingulate cortex, or ACC, located beneath the frontal lobe.
The monkeys explored touch targets on a computer screen, discovering which target triggered a juice reward. They then could repeatedly touch the target for more juice, after which the computer screen was withdrawn.
Researchers analyzed activity of the ACC cells at the time of four events -- an incorrect choice, the first reward, a repeated reward, and withdrawal of the task. Analyses revealed distinct types of activity in the ACC cells corresponding to each event.
"The ACC produces signals that discriminate between various behaviorally relevant positive and negative feedbacks," said Professor Emmanuel Procyk. "These signals governing exploration are believed to be among those that malfunction in addiction and mental illness."
The study appears in the journal Neuron.