Surveyor 2 - the ghost rocket

Surveyor 2 - ghost rocket or space junk?

In September 1966, the US launched a rocket carrying a Moon probe known as Surveyor 2. The mission was to land on the Moon and transmit data back to Earth. So-called "soft landings" had been done twice before, once by the USSR and once by the US. The cold-war space race was on.

The plan was that the probe photograph its own landing site. To do this, it would land, pause, then fire its engine and take off again, landing a second time. During this brief "bounce", the probe would examine the ground where it had landed.

Nothing was known about the Moon's surface. If humans were to walk there, it was important to know that they wouldn't fall into a subsurface cavern or be lost in quicksand. The probe was going to use photographs and radar to examine the structural integrity of the surface.

But it was all a moot point.

The Centaur booster successfully lifted the probe out of Earth orbit and towards the Moon before separating at a point between the Earth and the Moon. But the probe "experienced an asymmetrical failure" (one of the side engines conked out) during a later course correction and began to tumble uncontrolled. It crashed near Copernicus (see Bruce Rohrlach's brilliant photo).

The booster, a dead 41-foot long rocket, continued past the Moon. Being out of the Earth's gravity well, it was under the influence of the Sun's gravity, and so drifted further and further away. The US either didn't have the capability or the interest to track it, and it was lost.

Until now.

54 years later, nearly to the day, a relatively slow-moving object 6-14 metres in size was spotted approaching Earth. It's in a solar orbit, and will be briefly caught by Earth's gravity before wandering away again, like a golfer narrowly missing a putt.

If this really is the Centaur booster from 1966, the lesson is that little is ever lost in orbit.

Return of a lonely traveller, or space junk? It'll probably be seen again, but not for a long time.

UPDATE: in early December 2020, NASA confirmed that Near Earth Object 2020 SO is in fact the Centaur rocket from the 1966 Surveyor 2 mission. This had been done primarily with spectrographic analysis which determined what the object was made of. Orbital analysis also suggests that the rocket has made a few other close passes to Earth - we just didn't notice it.