Earth has another temporary satellite.
First spotted in 2013 (and later dug up in precovery images from 2012), object WT1190F orbits the Earth with a perigee somewhere below the geosynchronous ring and an apogee twice the distance to the Moon. There are no known manmade satellites with such an orbit, so initially, it was suspected to be a captured asteroid, but after the lesson of temporary satellite J002E3, everybody was a bit cautious about that.
J002E3 was discovered as a tiny “second moon” of Earth in 2002. Further observations determined it to be only a temporary satellite, with an orbit that oscillates between solar and Earth orbit on a regular basis. And the last time it was orbiting Earth was in 1971. That was during a time period when there were really a lot of eyes on the Moon, so how could such a large object have been missed? The puzzle became clear when its spectra was determined, and the object was found to be covered in a thin layer of titanium dioxide — paint, in other words. It was the long-lost S-IVB (the third stage of a Saturn V) from Apollo 12. It has since escaped back into solar orbit, and is still out there.
This object is probably also space trash. There are enough observations now that an estimate of its density can be made, and it’s extremely light. Perhaps a fuel tank, a spent booster stage (though it’s too small to be an S-IVB), an SLA panel . . . I heard one person say he hoped it would turn out to be the missing ascent stage from “Snoopy”, the Apollo 10 Lunar Module, which never landed on the Moon. That would be quite lovely — except for one thing.
It’s coming home. So if we’ve finally found Snoopy, we won’t have found it for long.
An object this small and in this chaotic an orbit is easily perturbed by the solar wind and the gravity of other bodies, including the Earth and Moon. Its orbit has become a suicidal one, and on November 13, it’s expected to impact the Earth’s atmosphere over the Indian Ocean. Probably very little of it will survive to the surface, but astronomers are flocking to Sri Lanka in hopes of observing and measuring the fireball it produces.
Who knows what mission this is really from? Could be Snoopy, could be discarded hardware from one of the Soviet Zond missions, could be a lot of things. But it’s gonna go out with a bang in a couple of weeks. 😉