Near-Earth asteroid passes over Atlantic Ocean

An asteroid with an estimated girth as large as a garbage truck soared within 7,500 miles of the Earth on Monday, June 30, as it passed harmlessly over the Atlantic Ocean, according to NASA's Jet Propulsion Laboratory (JPL).

The space rock, measuring 5 to 20 metres in diameter, followed the same near-Earth path that scientists had earlier predicted, looping around the planet in a boomerang-shaped trajectory, JPL spokesman D.C. Agle said.

Its nearest approach to Earth, about 7,500 miles, was 30 times farther away than the International Space Station, which orbits the planet at a distance of 250 miles.On a more celestial scale, the asteroid's closest distance to Earth was just 3 per cent of the 250,000 miles separating the Earth from the moon.

An object about the same size as Monday's near-Earth asteroid, designated by scientists as 2011 MD, zips past the planet at about the same distance every six years, according to JPL.Even if an asteroid the size of 2011 MD ever entered the Earth's atmosphere, it would likely burn up and cause no damage to the planet, JPL said.

-Science Daily

A super-elastic alloy which may resist quakes

Researchers in Japan have developed a super-elastic alloy, which can spring back to its original form in extreme temperatures, they said in a report recently, adding that they hope it may be used in buildings to absorb shocks from earthquakes.

The experts, who wrote about their invention in the journal Science, added a small amount of nickel to an iron-based alloy, and found that the new material can recover its original shape at any temperature from -196 to 240 degrees Celsius.

Lead author Toshihiro Omori at the Department of Materials Science, Graduate School of Engineering in Tohoku University, said this new material was far more elastic than other super-elastic alloys, which cannot revert to their original form outside the -20 to 80 degrees Celsius range.

"Our ferrous alloy has temperature insensitivity by one order of magnitude. This property is very important because materials are subject to change in temperature in most cases," Omori wrote in an email in response to questions from Reuters."Another advantage is its low cost. The raw material is cheap ... resulting in the potential for large scale applications," Omori wrote.The material may be used in environments that are constantly exposed to extreme temperatures, such as joints and controls in cars, planes and spacecraft, Omori and his colleagues said.It may also help buildings cushion stress and violent movement in earthquakes, the materials science experts added.

-Reuters