Planets

  1. Planets

    Catching a Comet’s Tail

    A closeup visit by a NASA spacecraft helps show how a comet gets its shape.

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  2. Earth

    Killer space rock snuffed out ancient life

    Rock fragments from Antarctica suggest a huge meteor struck Earth 250 million years ago.

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  3. Planets

    A planet from the early universe

    Astronomers have found the oldest and most distant planet known in the universe.

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  4. Planets

    Melting Snow on Mars

    Melting blankets of snow may have carved out Martian gullies.

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  5. Planets

    A planet’s slim-fast plan

    A planet orbiting very close to its sun can quickly lose weight.

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