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Plunging satellite could fall on the US
Source: Agencies |
September 24, 2011, Saturday
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NORTH America is back in the firing line as a defunct NASA satellite plunges toward Earth.
The research satellite - about the size of a bus - is likely to tumble to Earth sometime today, showering pieces over a still unknown part of the planet, according to NASA.
Scientists are unable to pinpoint the exact time and place where the Upper Atmosphere Research Satellite, or UARS, will return to Earth due to the satellite's unpredictable tumbles and changes in the thickness of the atmosphere, fueled in part by a recent powerful solar flare.
The solar flare released a blitz of highly charged particles called a coronal mass ejection in the direction of Earth. When the particles slam into the atmosphere, they cause it to heat up and expand, which in turn impacts the density of the air UARS is encountering as it tumbles uncontrollably in orbit.
Initially, scientists believed North America was out of the zone where up to 26 pieces of UARS debris, weighing a total of about 500 kilograms, would land or splash down.
There is now a low probability that debris will land in the United States, NASA said last night.
"The satellite's orientation apparently has changed and that is now slowing its descent," NASA said. "There is a low probability any debris that survives re-entry will land in the United States but the possibility cannot be discounted because of this changing rate of descent."
With most of the planet covered in water and vast uninhabited deserts and other land directly beneath the satellite's flight path, the chance that someone will be hit by falling debris is 1-in-3,200, NASA said.
The research satellite - about the size of a bus - is likely to tumble to Earth sometime today, showering pieces over a still unknown part of the planet, according to NASA.
Scientists are unable to pinpoint the exact time and place where the Upper Atmosphere Research Satellite, or UARS, will return to Earth due to the satellite's unpredictable tumbles and changes in the thickness of the atmosphere, fueled in part by a recent powerful solar flare.
The solar flare released a blitz of highly charged particles called a coronal mass ejection in the direction of Earth. When the particles slam into the atmosphere, they cause it to heat up and expand, which in turn impacts the density of the air UARS is encountering as it tumbles uncontrollably in orbit.
Initially, scientists believed North America was out of the zone where up to 26 pieces of UARS debris, weighing a total of about 500 kilograms, would land or splash down.
There is now a low probability that debris will land in the United States, NASA said last night.
"The satellite's orientation apparently has changed and that is now slowing its descent," NASA said. "There is a low probability any debris that survives re-entry will land in the United States but the possibility cannot be discounted because of this changing rate of descent."
With most of the planet covered in water and vast uninhabited deserts and other land directly beneath the satellite's flight path, the chance that someone will be hit by falling debris is 1-in-3,200, NASA said.
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