Spaceships like Voyager have long disproved the axiom that "what comes up, must come down" — but the rules still apply to the European Space Agency's GOCE satellite, which ran out of fuel last month and has been slowly making its way back to Earth ever since. The craft, designed to map our planet's gravitational field and weighs a full ton, is expected to reenter the atmosphere in spectacular fashion as early as today.

As is often the case with satellite reentry, no one's exactly sure when, where, or how GOCE will come crashing down. Much of the craft will burn up in this atmosphere, but there's at least a chance that some chunks will make it to the surface — the thought of a single flaming pound of white-hot space debris hitting your car or house is terrifying enough, but The New York TImes reports that pieces as large as 200 pounds could hit the ground. Fortunately, the fact that the planet is mostly water puts the odds in our favor: NASA's Upper Atmosphere Research Satellite and Russia's failed Mars probe Phobos-Grunt both landed without incident in the Pacific.

Update: The European Space Agency says the satellite caused no damage after re-entering Earth's atmosphere.