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Oct 11

WISE finds fewer asteroids near Earth

Source: NASA/WISE


Image credit: NASA/JPL-Caltech.

New observations by NASA's Wide-field Infrared Survey Explorer, or WISE, show there are significantly fewer  near-Earth asteroids in the mid-size range than previously thought. The findings also indicate NASA has found more than 90 percent of the largest near-Earth asteroids, meeting a goal agreed to with Congress in 1998.

Astronomers now estimate there are roughly 19,500 -- not 35,000 -- mid-size near-Earth asteroids. Scientists say this improved understanding of the population may indicate the hazard to Earth could be somewhat less than previously thought. However, the majority of these mid-size asteroids remain to be discovered. More research also is needed to determine if fewer mid-size objects (between 330 and 3,300-feet wide) also mean fewer potentially hazardous asteroids, those that come closest to Earth.

The results come from the most accurate census to date of near-Earth asteroids, the space rocks that orbit within 120 million miles (195 million kilometers) of the sun into Earth's orbital vicinity. WISE observed infrared light from those in the middle to large-size category. The survey project, called NEOWISE, is the asteroid-hunting portion of the WISE mission. Study results appear in the Astrophysical Journal. (read more)

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1
Oct 11

NGC 281: Living the High Life

Source: Chandra


Credits: X-ray: NASA/CXC/CfA/S.Wolk; IR: NASA/JPL/CfA/S.Wolk

A nebula with active star formation about 9,200 light years from Earth. (read the hole story)

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1
Oct 11

ESA's spacecraft reveals new anatomy around a black hole

Source: ESA


Artist's impression of the central engine of an active galaxy.
Image credits: NASA and M. Weiss (Chandra X-ray Center).

A fleet of spacecraft including ESA's XMM-Newton and Integral have shown unprecedented details close to a supermassive black hole. They reveal huge 'bullets' of gas being driven away from the 'gravitational monster'. (read more)

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