An 8-ton Chinese space lab will crash into Europe or the U.S. Don't panic yet.

Experts are warning that an eight-ton Chinese space laboratory that has a deteriorating orbit path will likely crash into Europe in early April—but there’s a bit of disagreement on exactly when and, indeed, where.

Tiangong-1 is a satellite laboratory that contains large amounts of hydrazine, which is a toxic and flammable chemical that can wreak all kinds of havoc on the human body, including poisoning the blood, kidneys, lungs, the central nervous system, and damage to eyes, nose, mouth, and respiration. It can also produce severe burns on the skin.

America’s Aerospace Corporation (AAC) predicts the first week of April for re-entry and the crash landing of some of the pieces, while the European Space Agency (ESA) has a much larger window of March 24 to April 19.

While it’s not clear just how much of the craft will incinerate on the way to Earth’s surface, AAC is predicting some of the chunks will survive—and if they do, they will scatter over the span of a few hundred kilometers.

The ESA is predicting that “Reentry will take place anywhere between 43ºN and 43ºS (e.g. Spain, France, Portugal, Greece, etc.). Areas outside of these latitudes can be excluded. At no time will a precise time/location prediction from ESA be possible. This forecast will be updated approximately every week in January and February.” However, a fresh report on this story is saying it could even end up in Northern U.S. states.

Chart showing the descent of the Tiangong-1. Image credit, Jonathan McDowell.

After the craft lost radio connection with China’s Space Agency after being launched in 2011, it began to slip into a lower and lower orbit, and it just started dipping into Earth’s atmosphere.

A somewhat alarming warning from Aerospace Corporation’s Center for Orbital and Reentry Debris Studies (CORDS) states: “Potentially, there may be a highly toxic and corrosive substance called hydrazine on board the spacecraft that could survive reentry. For your safety, do not touch any debris you may find on the ground nor inhale vapors it may emit.”

While craft like this frequently pass through Earth’s atmosphere, the concern is that this one is particularly large.

Jonathan McDowell, an astrophysicist from Harvard University, seems a bit less worried about the satellite than some, but he still has a note of caution, as he told The Guardian. “Every couple of years something like this happens, but Tiangong-1 is big and dense so we need to keep an eye on it.”