In October 2017 an unexpected visitor entered the inner sanctum of our Solar System. To the untrained eye it was merely a long, thin space rock, not unlike many others found between Mars and Jupiter. It's odd shape certainly was distinguishing, as was its strange tumbling rotation, but other than that, why get excited?

Further observations, however, showed at U1 or Oumuamua, was travelling at a great speed and had an hyperbolic trajectory and high orbital eccentricity, suggesting that it had come from somewhere in deep space - from another star system! So this was the first observed visitor from another solar system or debris cloud!

Yeah, its just a rock, I hear you say. Sure it is, but doesn't the lonely voyage of this over-sized space cigar(some might say pancake) make you wonder about the vastness of the cosmos. Just the return trip out of our solar system will take 20,000 years!

Very recently, a couple of scientists speculated that U1 might be part of an alien spacecraft. It's a long, long shot devoid of hard evidence, but it put Oumuamua in the media spotlight again and no doubt activated minds in the crackpot web.

The classic artist's impression. (U1 is small object (about 200m x 40 metres) so is only a little dot when observed.)



Nasa's gif of Oumuamua's (U1) wild orbit.