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Wednesday, June 16, 2010
Earth gravity and solar eclipse
A team of Chinese scientists is planning to conduct a once-in-a-century experiment on July 22, the day of the total solar eclipse, which would test the controversial theory that gravity drops slightly during a total eclipse.
According to a report in New Scientist, geophysicists from the Chinese Academy of Sciences are preparing an unprecedented array of highly sensitive instruments at six sites across the country to take gravity readings during the total eclipse due to pass over southern China on July 22.
The results, which will be analyzed in the coming months, could confirm once and for all that anomalous fluctuations observed during past eclipses are real.
The first sign that gravity fluctuates during an eclipse was in 1954, when French economist and physicist Maurice Allais noticed erratic behaviour in a swinging pendulum when an eclipse passed over Paris.
Pendulums typically swing back and forth as a result of gravity and the rotation of the Earth. At the start of the eclipse, however, the pendulum's swing direction shifted violently, suggesting a sudden change in gravitational pull.
In the run up to July's eclipse, Chinese researchers have prepared eight gravimeters and two pendulums spread across six monitoring sites.
At over five minutes, the event will be the longest total solar eclipse predicted for this century.
Cosmic rays accelerated by exploded stars
Using ESO’s Very Large Telescope and NASA’s Chandra X-ray Observatory, astronomers have shown that cosmic rays from the Milky Way are very efficiently accelerated in the remnants of exploded stars.
Cosmic rays are extremely energetic particles – mostly protons – moving at close to the speed of light. They originate from outside our Solar System and are constantly bombarding the Earth’s atmosphere at a rate of some 100,000 per square metre per second.
Shuttle Endeavour finally launched
Shuttle Endeavour finally roared to life and blasted off Wednesday on its sixth try, rocketing away through a hazy sky toward a Friday rendezvous with the International Space Station from Kennedy Space Center.
Multiple pieces of foam insulation fell from the ship's external tank during the early moments of flight, but it was not immediately clear whether the shuttle's fragile heat shield suffered any significant damage.
With commander Mark Polansky and pilot Douglas Hurley at the controls, Endeavour's three main engines ignited in staggered sequence and throttled up to full thrust, followed seconds later by ignition of the shuttle's twin solid-fuel boosters at 6:03:10 p.m. EDT.
Friday, June 11, 2010
President Obama hails successful Hubble repair
President Barack Obama called the crew of the shuttle Atlantis late Wednesday and congratulated the astronauts on the successful overhaul of the Hubble Space Telescope. He also promised to name a new NASA administrator soon, although he provided no clues as to who might get the nod.
Shuttle Endeavour launch on sunday postponed
NASA on Sunday postponed the launch of space shuttle Endeavour for the day due storms near Kennedy Space Center.
NASA will next try to launch the shuttle on Monday at 6:51 p.m.
Endeavour's launch was postponed twice last month because of a liquid hydrogen leak.
Endeavour, carrying seven astronauts and a key component for Japan's Kibo science laboratory, is to head to the International Space Station for a 16-day mission. Five spacewalks are planned for the crew after the shuttle docks.
Tuesday, June 8, 2010
Indian moon mission saved
India's only satellite Chandrayaan -I orbiting moon came close to overheating and failure but scientists improvised to save it.
Last month the satellite lost a critical instrument called the star sensor. The sensor helps the $80-million satellite stay oriented so its cameras and other recording equipment are constantly aimed at the lunar surface. Without the sensor , the mission is useless.
Indian Space Research Organisation (ISRO) team used other systems such as an antenna mechanism and gyroscope to make sure that satellite was " looking at the moon". Now, the mission is safe and the systems are working.
Chandrayaan is scheduled to last two years. Scientists hope that Chandrayaan project will boost India's capacity to build more efficient rockets and satellites.
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