The dead Chinese space lab that's been crashing to Earth since at least 2016 is projected to finally smash through the atmosphere and into land (or sea) sometime Sunday night. Per NPR, the European Space Agency believes that what remains of Tiangong-1 after its burn up during re-entry will make landfall in a 4-hour window around 9pm EST. While the timeline for re-entry has tightened, experts are still unable to say exactly where the debris will land, or even close to where. Based on Tiangong 1's orbit, it will come to Earth between latitudes of 43 degrees north and 43 degrees south, or roughly somewhere over most of the US, China, Africa, southern Europe, Australia, and South America. Based on its size, only about 10% of the spacecraft will likely survive being burned up on re-entry, mainly heavier components such as its engines.
So, fret not. The chances of anyone on Earth being hit by debris are considered less than one in a trillion. However, that doesn't explain exactly why scientists are unable to say where Tiangong-1 will hit. According to Live Science, the variable density of Earth's atmosphere is partially to blame for the uncertainty. Another variable: Tiangong-1's orientation. Depending on the space lab's alignment, drag could cause it to fall faster or more slowly. For the armchair astronomers out there, there are several websites tracking the re-entry, including Aerospace.org. Scientists say the re-entry window will narrow as Tiangong-1 descends closer to Earth. (Read more Tiangong-1 stories.)