China's defunct and reportedly out-of-control Tiangong 1 space station is expected to re-enter Earth's atmosphere sometime this weekend. It poses only a slight risk to people and property on the ground, since most of the bus-size, 8.5-ton vehicle is expected to burn up on re-entry, although space agencies don't know exactly when or where that will happen. The European Space Agency predicts the station will re-enter the atmosphere between Saturday morning and Sunday afternoon—an estimate it calls "highly variable," likely because the ever-changing shape of the upper atmosphere affects the speed of objects falling into it. The Chinese space agency's latest estimate puts re-entry between Saturday and Wednesday.
Western space experts say they believe China has lost control of the station. China's chief space laboratory designer Zhu Zongpeng has denied Tiangong was out of control, but hasn't provided specifics on what, if anything, China is doing to guide the craft's re-entry, the AP reports. Based on Tiangong 1's orbit, it will come to Earth somewhere 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. Out of range are Russia, Canada, and northern Europe. 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. The chances of anyone on Earth being hit by debris is considered less than one in a trillion.