A new study suggests yet another theory for a possible extra planet in our solar system, likely of a size between Mercury and ...

The uncommon interstellar visitor, comet 3I/ATLAS, is captivating astronomers worldwide as it races through our solar system at an astonishing speed of roughly 130,000 mph (219,000 km/h).

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This October, as the interstellar comet 3I/ATLAS passes through our solar system, it offers a rare scientific opportunity. For the first time, a suite of spacecraft designed for Mars and Jupiter ...