Oumuamua is an elongated, cigar-shaped object that passed through our solar system in 2017. It is the first known interstellar object detected, meaning it originated from outside our solar system. Scientists believe it traveled from another star system, making its journey through space for millions of years before encountering the Sun. Discovered by astronomers using the Pan-STARRS1 telescope in Hawaii, Oumuamua exhibited unusual characteristics, such as its rapid speed and changing brightness. These features led to various theories about its composition, with some suggesting it could be a comet, asteroid, or even a piece of alien technology, though no definitive conclusion has been reached.