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LOS ANGELES, April 7 (Xinhua) -- Using NASA's Galaxy Evolution Explorer (GEE) satellite, U.S. astronomers are hunting for nearby, hard-to-see stars which could very well be home to the easiest-to-see alien planets, it was announced on Thursday.U.S. astronomers are ferreting out the new targets after the glare of bright, shining stars has frustrated most efforts at visualizing distant worlds, NASA's Jet Propulsion Laboratory (JPL) said.So far, only a handful of distant planets, or exoplanets, have been directly imaged. Small, newborn stars are less blinding, making the planets easier to see, but the fact that these stars are dim means they are hard to find in the first place."Fortunately, the young stars emit more ultraviolet light than their older counterparts, which makes them conspicuous to the ultraviolet-detecting GEE," JPL said in a press release."We've discovered a new technique of using ultraviolet light to search for young, low-mass stars near the Earth," said David Rodriguez, a graduate student of astronomy at University of Californian, Los Angeles. "These young stars make excellent targets for future direct imaging of exoplanets."Young stars, like human children, tend to be a bit unruly -- they spout a greater proportion of energetic X-rays and ultraviolet light than more mature stars. In some cases, X-ray surveys can pick out these youngsters due to the "racket" they cause. However, many smaller, less "noisy" baby stars perfect for exoplanet imaging studies have gone undetected except in the most detailed X-ray surveys. To date, such surveys have covered only a small percentage of the sky, according to JPL in Pasadena, Los Angeles.Rodriguez and his team figured that the GEE, which has scanned about three-quarters of the sky in ultraviolet light, could fill this gap.Astronomers compared readings from the telescope with optical and infrared data to look for the telltale signature of rambunctious junior stars. Follow-up observations of 24 candidates identified in this manner determined that 17 of the stars showed clear signs of youth, validating the team's approach, JPL said."The Galaxy Evolution Explorer can readily select young, low- mass stars that are too faint to turn up in all-sky X-ray surveys, which makes the telescope an incredibly useful tool," Rodriguez said in the release.

WASHINGTON, May 4 (Xinhua) -- The U.S. National Aeronautics and Space Administration (NASA) announced Wednesday that its Gravity Probe B (GP-B) mission has confirmed two key predictions derived from Albert Einstein's general theory of relativity, which the spacecraft was designed to test.The experiment, launched in 2004, used four ultra-precise gyroscopes to measure the hypothesized geodetic effect, the warping of space and time around a gravitational body, and frame- dragging, the amount a spinning object pulls space and time with it as it rotates.GP-B determined both effects with unprecedented precision by pointing at a single star, IM Pegasi, while in a polar orbit around Earth. If gravity did not affect space and time, GP-B's gyroscopes would point in the same direction forever while in orbit. But in confirmation of Einstein's theories, the gyroscopes experienced measurable, minute changes in the direction of their spin, while Earth's gravity pulled at them.The findings are available online in the journal Physical Review Letters."Imagine the Earth as if it were immersed in honey. As the planet rotates, the honey around it would swirl, and it's the same with space and time," said Francis Everitt, GP-B principal investigator at Stanford University. "GP-B confirmed two of the most profound predictions of Einstein's universe, having far- reaching implications across astrophysics research."GP-B is one of the longest running projects in NASA history, with agency involvement starting in the fall of 1963 with initial funding to develop a relativity gyroscope experiment. Subsequent decades of development led to groundbreaking technologies to control environmental disturbances on spacecraft, such as aerodynamic drag, magnetic fields and thermal variations. The mission's star tracker and gyroscopes were the most precise ever designed and produced.GP-B completed its data collection operations and was decommissioned in December 2010."The mission results will have a long-term impact on the work of theoretical physicists," said Bill Danchi, senior astrophysicist and program scientist at NASA Headquarters in Washington. "Every future challenge to Einstein's theories of general relativity will have to seek more precise measurements than the remarkable work GP-B accomplished."

SAN FRANCISCO, April 18 (Xinhua) -- Apple Inc. has sued Samsung Electronics Co. over patent infringement in a latest suit, U.S. media reported Monday.The suit, filed last Friday in U.S. District Court in Northern California, alleged that Samsung's smartphones, such as "Glaxy S 4G" and "Nexus S," and the Galaxy line of tablet computers violated Apple's patent and trademark, according to All Things Digital, a technology and startup company news site."It's no coincidence that Samsung's latest products look a lot like the iPhone and iPad, from the shape of the hardware to the user interface and even the packaging," the report quoted an Apple representative as saying.Intellectual property suits can be often seen among mobile computing rivals, including suits between Microsoft and Motorola, a suit by Oracle against Google, and Apple's patent dispute with Nokia and HTC.Although Samsung supplies chips for a number of Apple products, Apple CEO Steve Jobs once openly mocked Samsung and other tablet makers as "copycats" during the iPad2 launch. Last month, Apple is reportedly partnering with China's Taiwan Semiconductor Manufacturing Co. to make iPad chips.

UNITED NATIONS, April 7 (Xinhua) -- To celebrate the 50th anniversary of the first human space flight, accomplished on April 12, 1961 by Soviet cosmonaut Yuri Gagarin, the Russian Permanent Mission to the United Nations, the Russian Federal Space Agency and the ITAR-TASS information agency organized an exhibition which was opened here on Thursday."The first human space flight is not one of the most significant events of the past century, but of human history in general," Vitaly Churkin, the Russian permanent representative to the UN, said at the opening ceremony."It's a symbol of courage, thirst for knowledge, and progress," Churkin said.The exhibition contained archival photos telling the story of the first human space flight and of those who made it possible, and historic pictures of Gagarin.As part of the celebration of human space flight's 50th anniversary the UN Postal Administration designed postal stamps which will be issued on April 12, to tell the story of progress that humankind has made beyond earth's boundaries, as Kiyo Akasaka, Under-Secretary-General for Communications and Public Information put it."Fifty years have passed since that amazing voyage, but the legend of Gagarin's courage and journey to the 'final frontier' continues to be a source of inspiration for space exploration for peoples and nations around the world," Akasaka said at the opening of the exhibition.According to Akasaka, the exhibition "sparks people's imagination about what is possible through the peaceful use and exploration of outer space."Other attendees included Russian cosmonaut Oleg Kotov.Gagarin, also known as the Columbus of the Cosmos, traveled into outer space on the height of the Cold War when the Berlin Wall was built, at a moment when it was hardly impossible to imagine that more than 15 nations would work together in humanity' s permanent space outpost -- the International Space Station.The Russian icon of space spoke the historic words "the earth is blue, how wonderful. It is amazing."On Thursday the UN General Assembly adopted a resolution declaring April 12 as the International Day of Human Space Flight.

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