Fragments of NASA's 12,500-pound, 35-foot long Upper Atmosphere Research Satellite are expected to crash to Earth Friday.

The American space agency decommissioned the satellite in 2005 because other satellite could perform its functions.

NASA estimates the odds of the UARS hitting someone would be 1 in 3,200, which is quite high compared with the 1 in 13,983,816 odds of winning a six-digit lottery.

The projected crash zone between 57 degrees north latitude and 57 degrees south latitude covers almost the entire Earth, particularly its inhabited parts. But the craft has a higher chance of landing into the open ocean than on land.

The Friday forecast is also tentative since the decommissioned satellite could hit the planet anytime between Thursday and Sunday.

Once the satellite hits the Earth, its estimated 26 pieces are expected to survive the re-entry burn, but spread within a linear field 500 miles long. NASA said the largest piece would be about 300 pounds.

UARS is the largest piece of NASA space junk to hit the earth in three decades. It is expected to create a light show as the satellite partially burns during reentry and create fireballs visible even during daytime after the satellite breaks into smaller pieces.

NASA launched UARS in 1991 on space shuttle Discovery. The satellite roamed the space for 14 years studying the atmosphere. Among the tasks that it performed were the measurement of chemicals that damage the ozone layer, aerosols from the Mount Pinatubo eruption and changes in solar radiation that affect the upper atmosphere.

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