Was it sent by aliens? The curious case of the giant space rock

A scientific paper led by two researchers at Harvard University made a splash this week by claiming that a cigar-shaped rock zooming through our solar system may have been sent by aliens.

The researchers noted in a pre-print of the article that it was an “exotic scenario”, but that “Oumuamua may be a fully operational probe sent intentionally to Earth vicinity by an alien civilisation.”

Oumuamua, the first interstellar object known to enter our solar system, accelerated faster away from the Sun than expected, hence the notion that some kind of artificial sail that runs on sunlight – known as a light sail – may have helped push it through space.

“Currently there is an unexplained phenomena, namely, the excess acceleration of Oumuamua, which we show may be explained by the force of radiation pressure from the sun,” co-author and Harvard astrophysicist Shmuel Bialy said via email Tuesday.

“However this requires the body to have a very large surface and be very thin, which is not encountered in nature.”