ʻOumuamua was the first object seen passing through our solar system from interstellar space. It was long, tumbling, and sped up slightly as it left. Harvard astronomer Avi Loeb suggested it could be alien technology. Most astronomers favour a natural explanation.
Truth label: Debated. Serious people disagree. You get both sides.
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The puzzle
Its small push away from the Sun had no visible gas jet, which comets usually show.
Natural ideas
Suggestions include a fragment of hydrogen ice or a piece of a shattered planet.
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- Not the last. More interstellar visitors have been found since, including a comet in 2019 and 3I/ATLAS in 2025.
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What made ʻOumuamua special?
It came from another star system. It was the first known interstellar object.
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