Washington, March 22 : A new study has determined that almost a quarter of the world''s land area is degrading, often in very productive areas.

Land degradation, which is the decline in the quality of soil, water and vegetation, is of profound importance, but until now, there have been no consistent global data by which to assess its extent and severity.

Now, a new study published in the journal Soil Use and Management attempts for the first time to measure the extent and severity of land degradation across the globe and concludes that 24 percent of the land area is degrading - often in very productive areas.

It measures global land degradation based on a clearly defined and consistent method using remotely sensed imagery.

Washington - Two astronauts from the Discovery space shuttle on Saturday began a second spacewalk to perform maintenance work on the International Space Station, reported NASA, the US space agency.

US astronauts Steve Swanson and Joseph Acaba will swap out batteries, fasten an antenna and install equipment for external storage, reported NASA.

The spacewalk is expected to last six and a half hours.

On Friday, the Discovery crew completed installation of the station's final pair of solar panels, which will expand the satellite's power supply.

Washington, March 21 : Studying the landing approaches of three species of bats, a Brown University-led research team found that not all bats arrive at their daytime perches the same way.

The researchers revealed that the study involved two species of bats that live in caves, and one that roosts in trees.

Their findings attain significance because they may offer new insights into how the second-largest order of mammals evolved.

Washington, Mar 21 : Researchers from University of Washington have found a novel way to prevent bone loss during spaceflight.

Studies have shown that the absence of gravity is causing astronauts on the International Space Station to lose up to 10 times more bone mass in key regions of the body each month than most post-menopausal women do in the same period of time back here on Earth.

While using bedrest as an analog of spaceflight, scientists could able to prevent bone loss in a specific region of the hip.

Paris, March 21: The European Space Agency's GOCE satellite has completed its early orbit phase.

During the critical Launch and Early Orbit Phase, beginning with separation from its booster on March 17, GOCE (Gravity field and steady-state Ocean Circulation Explorer) was checked out to confirm that all of its control systems are operating normally.

The end of the Launch and Early Orbit Phase (LEOP) came overnight after GOCE (Gravity field and steady-state Ocean Circulation Explorer) was switched to Fine Pointing Mode.

It seems that after defence and counter-terrorism, India and Israel are coming together in a big way in the field of space technology.

With a bid to boost up its intelligence acquisition after the 26/11 terror attacks, India has acquired a high-precision spy satellite from Israel.

It is learnt that the 300 kilogram satellite named as Radar Satellite (RISAT-2) will be launched using the Indian rocket the Polar Satellite Launch Vehicle (PSLV) in the first week of April from Sriharikota in Andhra Pradesh.