The potentially hazardous asteroid ‘(101955) 1999 RQ36’ has a one-in-a-thousand chance of impacting the Earth, and more than half of this probability indicates that this could happen in the year 2182, based on a global study in which Spanish researchers have been involved. Knowing this fact may help design in advance mechanisms aimed at deviating the asteroid’s path.
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India today successfully conducted the test fire of an interceptor missile to establish a Ballistic Missile defence (BMD) shield as part of the network-centric warfare.The mission was conducted successfully when the surface to surface Prthivi missile, described as targetted enemy missile, test fired from the launch complex of the Integrated Test Range (ITR) at Chandipur-on-sea, was destroyed in mid air by an Advanced Air Defence (AAD), a single stage anti ballistic missile, test fired from the Wheeler Island in the Bay of Bengal.With this India has joined the elite club of nations having this technology.
Dark energy has the cosmoslogists scratching their heads. Observations taken by NASA’s Hubble Space Telescope and future space telescopes will be needed in order to determine the properties of dark energy, which makes up about 70 percent of the universe. Probing dark energy, the energy in empty space causing the expanding universe to accelerate, calls for accurately measuring how that expansion rate is increasing with time. Dark energy is thought to drive space apart.
Astronomers theorize that the faster expansion rate is due to a mysterious, dark force that is pulling galaxies apart. Astronomers used NASA’s Hubble Space Telescope to hunt for supernovae (an energetic explosive event that occurs at the end of a star’s lifetime), using their brightness, astronomers could measure if the universe was expanding faster or slower in the distant past. In its search, Hubble discovered 42 new supernovae, including six that are among the most distant ever found. The farthest supernovae show that the universe was decelerating long ago, but then “changed gears” and began to accelerate.
Albert Einstein coined the term “cosmological constant” to represent the possibility that even empty space has energy and couples to gravity. Like other astronomers of the time, he thought that the universe was static and so proposed there was a repulsive force from space that kept the universe in balance.
Einstein discarded his own findings in 1929, when Edwin Hubble found through his research that the universe was expanding and not
static. Today, new data from Hubble may well prove Einstein was on the right track. The pull of gravity and the push of dark energy have been trying to outmuscle each other since the beginning of time. About seven billion years ago, dark energy got the upper hand because the universe had grown so large and matter (the source of gravity) had expanded and scattered.
Unstable dark energy could cause a “big rip” (the universe expands violently, then the stars, planets and atoms come unglued) or a “big crunch” (the universe implodes or compresses). Cosmologists believe about 70 percent of the universe consists of dark energy, 25 percent is dark matter, and only four percent normal matter (the stuff that stars, planets and people are made of). Hubble observations suggest the dark energy may be Einstein’s cosmological constant, an energy percolating out of the vacuum of the space between galaxies. The energy of the universe is dominated by empty space emitting a repulsive form of gravity that is pushing the universe apart. But what does all this mean to Earth? Even if Einstein’s theory was correct, we won’t have to be concerned about the “dark side” for about 30 billion years, according to Hubble researchers.
For further information, visit: http://universe.gsfc.nasa.gov/progr am/darkenergy.html
source:http://www.nasa.gov/missions/deepspace/f_dark-energy.html
A camera aboard NASA’s Mars Odyssey spacecraft has helped develop the most accurate global Martian map ever. Researchers and the public can access the map via several websites and explore and survey the entire surface of the Red Planet.The map was constructed using nearly 21,000 images from the Thermal Emission Imaging System, or THEMIS, a multi-band infrared camera on Odyssey. Researchers at Arizona State University’s Mars Space Flight Facility in Tempe, in collaboration with NASA’s Jet Propulsion Laboratory in Pasadena, Calif., have been compiling the map since THEMIS observations began eight years ago.
The pictures have been smoothed, matched, blended and cartographically controlled to make a giant mosaic. Users can pan around images and zoom into them. At full zoom, the smallest surface details are 100 meters (330 feet) wide. While portions of Mars have been mapped at higher resolution, this map provides the most accurate view so far of the entire planet.
The new map is available at: http://www.mars.asu.edu/maps/?layer=thm_dayir_100m_v11 .
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