Extraterrestrial: The First Sign of Intelligent Life Beyond Earth

by Avi Loeb

Briefly ignore what the object is composed of and let’s consider more carefully its shape. No one at a breakfast table would ever confuse a cigar for a pancake. They are dramatically different. So are we really left to choose between these two outlier shapes when we envision ‘Oumuamua tumbling through space? Yet another scientist, an astrophysicist at McMaster University, went back to the evidence to see if he could provide an answer. He evaluated all the brightness models the data allowed and concluded the likelihood of ‘Oumuamua being cigar-shaped was small and the likelihood of ‘Oumuamua being disk-shaped was about 91 percent. You should keep this percentage in mind when you see the umpteenth artist’s rendering of ‘Oumuamua as a cigar-shaped rock. You should also keep it in mind when reading any explanation for a naturally occurring oblong object, such as the low probability process of melting and tidal stretching along a rare trajectory that passes very close to a star, the value of which is mooted when it comes to ‘Oumuamua, given this analysis. Is there a simpler way to achieve the required surface-to-volume ratio for a pancake-shaped object? Yes, there is. You could build a thin, sturdy piece of equipment capable of deviating due to the effects of solar-radiation pressure to exactly such specifications.