A one-ton European gravity-mapping satellite is expected to re-enter Earth’s atmosphere and fall to the planet's surface in pieces on Sunday night, European Space Agency, or ESA, said on Friday, adding that they could not precisely say where the fragments would fall.

The European agency’s Gravity field and steady-state Ocean Circulation Explorer, or GOCE, satellite was launched on March 17, 2009, but it ran out of fuel in October. The GOCE has been dropping toward Earth ever since, and the ESA predicts that the satellite will reach Earth’s surface late Sunday or early Monday.

“When and where these parts might land cannot yet be predicted, but the affected area will be narrowed down closer to the time of re-entry,” the ESA said in a statement.

On Friday morning, the satellite was about 105 miles above Earth’s surface -- some 56 miles lower than its normal orbit. According to an ESA update, the satellite will disintegrate once it hits a 50-mile distance from Earth, adding that the “spacecraft continues to perform excellently” at these extreme conditions.  

According to Heiner Klinkrad, head of ESA's Space Debris Office, the satellite might break into a large number of fragments, most of which will burn up before it reaches Earth’s surface.

“A small fraction of the initial spacecraft mass – about 20% or 200kg – is expected to reach ground, distributed across dozens of fragments, spread over a sizable re-entry ground swath,” Klinkrad said in a blog post.

He affirmed that the odds of people being hit by a GOCE fragment were remote, adding that no man-made space objects that have re-entered Earth’s atmosphere have caused injury to humans.

“Statistically speaking, it is 250,000 times more probable to win the jackpot in the German Lotto than to get hit by a GOCE fragment,” Klinkrad said.

The 17.4 feet long satellite has been orbiting Earth at the lowest altitude of any research satellite exposing it to drags from the outer edges of Earth’s atmosphere, according to ESA.

The space agency said that the situation is being continuously watched by its Space Debris Office, which will periodically issue re-entry predictions.

The GOCE satellite can be tracked using a widget at the satellite tracking website N2YO.com.