Parts of giant Nasa satellite to crash to Earth, posing low risk | Nasa
Parts of a giant NASA satellite will crash into Earth on Tuesday evening, the US space agency warns – but the risk of being hit is extremely low.
The roughly 600-kilogram spacecraft, one of twin probes launched in 2012 to study the Van Allen radiation belt, is expected to reenter the Earth’s atmosphere around 7:45 p.m. EDT, according to the U.S. Army Space Force.
Most of the craft, according to a forecast released Monday, will burn upon its return, but some components are expected to survive. There is a small chance, which the Space Force calculates to be 1 in 4,200, that someone on Earth could be injured.
“NASA and the Space Force will continue to monitor re-entry and update forecasts,” the statement said, adding that there was an initial uncertainty of plus or minus 24 hours in the calculations.
Debris falling from space is not uncommon, and Wired reported in 2009 that over a 40-year period, about 5,400 tons are estimated to have survived re-entry.
But the chances of being affected are low because about 71% of the Earth’s surface is covered in water. A 2011 space.com report said the overall risk of someone being harmed was 1 in 3,200, and much less for any given individual. “The chances of you being hit are one in several billion, so pretty low for any one person,” Mark Matney, a scientist in the Orbital Debris Program Office at NASA’s Johnson Space Center in Houston, told the outlet.
Lottie Williams, a resident of Tulsa, Oklahoma, who was walking in a park in January 1997, was not so lucky when she saw a sudden flash of flight, followed by a six-inch piece of metal striking her in the shoulder.
The small blackened fragment has never been formally identified as space junk. But the time and location were confirmed by NASA to be consistent with the reentry and breakup of the second stage of a Delta rocket that had been in orbit for months. And Williams, who was uninjured, remains the only person known to have been hit by falling manufactured space debris.
On Sunday, a piece of meteor crashed into the roof of a house in Germany, one of 15,000 to 17,000 meteorites that reach Earth each year, although the majority end up at the bottom of the ocean.
The Space Force’s advisory on Tuesday’s satellite crash focuses more on where it came from than where or when it will land. The craft is Van Allen Probe A, launched with its twin, Van Allen Probe B, from Cape Canaveral, Florida, on August 30, 2012, on a mission to study the Van Allen belts of charged particles trapped by the Earth’s magnetic field.
The probes were deactivated in 2019 when they ran out of fuel and were no longer able to orient towards the sun. Initial calculations that they would re-enter Earth’s atmosphere in 2034 proved inaccurate, although the second probe is not expected to return until the end of that decade.
