China's 8-ton space station Tiangong-1 is expected to come crashing back to Earth. It isn't yet clear where it will exactly land and when this will happen.
However, when it does fall, is there any danger it could hit someone on the planet?
Some Parts Of Tiangong-1 May Not Be Incinerated
Chinese officials said that most parts of the space lab will burn up during its fall. However, there are parts that may not be incinerated, particularly the heaviest and densest ones such as those that make up the spacecraft's engine.
Probability Of Causing Danger Is Low
Still, the chances of these parts hitting somebody on the head is considered small. For one, this debris could end up in the water as about 71 percent of Earth is covered in water. The 29 percent of our planet's surface is entirely uninhabited. At least half of the world's population is crammed on 2.9 percent of the Earth's surface.
Nonetheless, China said that it would carefully monitor the descent of the spacecraft and inform the United Nations when the spacecraft starts its final plunge.
"The probability of endangering and causing damage to aviation and ground activities is very low," China told the UN's Committee on the Peaceful Uses of Outer Space. "China will make strict arrangements to track and closely monitor Tiangong-1 in its orbital development and will publish a timely forecast of its re-entry."
Caveats
Most orbits, however, are designed to maximize the time that spacecraft spend over dry land. It means that China's Tiangong-1, which flew at about 43º inclination to the equator, could have more land under its path particularly now when it is falling.
China and many experts believe that the probability of a space debris from the Chinese space lab crashing into somebody's head is small, but this is not entirely impossible. In 1997, a woman in Oklahoma was hit by a debris from a rocket.
Space Junk Survivor
Lottie Williams lived to tell the tale as a space junk survivor. She was at a park when she saw what appeared to be a shooting star. A little while later, she was hit on her shoulder by a 6-inch piece of black metallic material.
She later learned that she was possibly hit by a piece from a Delta II rocket body that reentered the atmosphere. NASA tests revealed that the characteristics of the fragment were consistent with those of the materials of the rocket.
"It looks as though one lady who was standing outside, early morning in Tulsa, Okla., was actually struck by the piece on the back," said Nicholas Johnson, who was NASA's chief scientist for orbital debris at the time. "It was so light-weight that it really hit her like a feather, or a leaf floating off a tree."
