Mysterious interstellar object could be 'lightsail' sent from another civilization

NASA may have ruled that Oumuamua, the first interstellar object ever spotted in our system is a "metallic or rocky object" approximately 400 meters in length and 40 meters wide, but a new study from the Harvard Smithsonian Center for Astrophysics says it could be something much more exciting - it could be "a lightsail of artificial origin" sent from another civilization.