Astronomers have been left puzzled by two interstellar visitors that defy conventional explanations. The first, 'Oumuamua, discovered in October 2017, exhibited unusual acceleration and an elongated shape, sparking debates about its composition and origin.
The second, 2I/Borisov, spotted in August 2019 by amateur astronomer Gennady Borisov, is suspected to be a rogue comet. Both objects have challenged existing theories about interstellar material, particularly due to their unexpected metallic properties.
Scientists are now questioning how often such objects visit our solar system and what they can reveal about distant star systems. The peculiarities of 'Oumuamua, including its lack of a comet tail despite passing close to the Sun, have led to speculation ranging from exotic ice compositions to artificial origins.
