Comets and asteroids preserve the building blocks of our solar system and should help explain its origin. But there are unsolved puzzles. For example, how did icy comets obtain particles that formed ...

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"We have been calling Uranus an ice giant, but we don't really know its nature." When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. Astronomers say ...

Washington, D.C.— Comets and asteroids preserve the building blocks of our Solar System and should help explain its origin. But there are unsolved puzzles. For example, how did icy comets obtain ...