In November, an approximately 1-meter piece of space junk burnt up in the Earth's atmosphere and fell into the Indian Ocean, making a fiery spectacle of itself. At the time space scientists weren't sure about the origin of the object, named WT1190F. Since then, there has been a flurry of activity to try and trace the trajectory of the debris back to its origin.

Now according to a report in Nature, scientists have a leading candidate. The space debris appears likely to have come from the translunar injector of Lunar Prospector, a spacecraft launched by NASA in 1998. This part of the rocket would have boosted the spacecraft out of Earth orbit and toward the Moon.

By comparing observations from telescopes since 2009, scientists found the object had a stretched out path that brought it beyond the Moon's orbit, which was consistent with a Moon rocket. They believe the object only could have survived in the Earth-Moon system for a decade or slightly longer. Additionally, spectra from the debris showed the presence of titanium oxide and hydrogen, which were consistent with the injector's titanium case.

The Lunar Prospector spent 1.5 years mapping the low polar regions of the Moon, including searching for ice, before it deliberately crashed into a crater near the lunar south pole.

Before it reentered Earth's atmosphere, the debris intrigued skywatchers because it offered a rare opportunity to plan for and track the return of a piece of space junk. About a dozen veteran US, European, and UAE observers of spacecraft re-entries flew aboard a chartered a Gulfstream 450 business jet, affording a view above the clouds and haze. It fell into the ocean about 100km south of Sri Lanka at approximately 06:20 UT on Nov. 13.