1. Planets

    Early Earth may have been a hot doughnut

    Synestia is the name some scientists are giving to the smooshed shape Earth might have developed after undergoing a violent cosmic smashup early in its infancy.

  2. Planets

    What the Curiosity rover has learned about Mars so far

    Scientists take stock of what the Curiosity rover has learned after five years on Mars — and what else it may turn up in the next year or so.

  3. Planets

    Early solar system may have slung giant mud balls

    The first asteroids may have been great balls of mud. That could solve some puzzling traits of meteorites.

  4. Planets

    Small, distant worlds are either big Earths or little Neptunes

    The Kepler space telescope data are in. They split Earth-like exoplanets into two groups and reveal 10 new rocky planets in the ‘Goldilocks’ zone.

  5. Planets

    Jupiter may be the solar system’s oldest planet

    Jupiter’s early existence may explain the odd arrangement of planets in the solar system, a new study suggests.

  6. Planets

    Hot, hot planet sets sizzling new record

    Astronomers have discovered an odd new exoplanet. Called KELT 9b, is the hottest non-star known.

  7. Planets

    Jupiter gets surprisingly complex new portrait

    NASA’s Juno spacecraft has sent back unexpected details about Jupiter, giving scientists their first close-up of this gas giant.

  8. Planets

    Scientists Say: Eclipse

    How the sun, moon and Earth line up determines whether there’s a solar or lunar eclipse.

  9. Planets

    How Earth got its moon

    How did our moon form? Scientists are still debating the answer. It may be the result of some one big impact with Earth — or perhaps many small ones.

  10. Planets

    Analyze This: The masses of planets

    Scientists discovered a solar system with planets that are similar in size and mass to Earth. Using data, we take a closer look at that similarity.

  11. Planets

    Scientists Say: Dwarf planet

    Dwarf planets are distinct from the full-size models. A little too small, they also have a lot of space stuff filling their path around the sun.

  12. Planets

    Scientists Say: Goldilocks zone

    Not too hot, not too cold. Just right. This is the region around a star where water could be a liquid, instead of a solid or gas.