1. Planets

    Cousin Earth

    Astronomers have found a solid, Earthlike planet just 15 light-years beyond the solar system.

  2. Planets

    Chaos Among the Planets

    The screwball travels of four giant planets may have reshaped the early solar system.

  3. Space

    Killers from Outer Space

    A newly revised scale rates the risk that an asteroid may crash into Earth and wipe out life as we know it.

  4. Planets

    Solving a Sedna Mystery

    Astronomers are learning more about the most-remote object known in the solar system.

  5. Space

    Return to Space

    NASA is readying the space shuttle Discovery for its first launch in more than 2 years.

  6. Space

    Super star cluster in the neighborhood

    Astronomers have spotted an amazingly compact grouping of stars in the Milky Way.

  7. Space

    No Fat Stars

    Stars in the Milky Way can weigh no more than 150 times the sun's mass.

  8. Space

    Dark galaxy

    Astronomers have spied a massive galaxy that appears to contain no stars.

  9. Planets

    Sounds of Titan

    A space probe touches down on an alien, but eerily familiar world and samples its music.

  10. Space

    Black hole journey

    Research on weird, invisible objects called black holes might help explain how the universe began.

  11. Planets

    Unveiling Titan

    A space probe that landed on Saturn's frigid moon Titan found a landscape that looks a lot like Earth.

  12. Planets

    Icy Orbs at the Solar System’s Edge

    A ring at the solar system's outskirts appears to contain smaller objects than expected.