Mars might be made of mashed-up baby planets
From trace elements inside Martian rocks, researchers are piecing together how the planet came to be. (NASA/JPL-Caltech /)The solar system wasn’t always the set of calmly spinning orbs we see today. In its earliest epochs, mini-planets swarmed around the sun, mixing together in cataclysmic smash-ups. This game of cosmic billiards played out so violently that worlds like Earth and Mars started out their lives as largely liquid gobs of smoothly blended rock. Or so many researchers have thought. Now, careful scrutiny of two ancient hunks of Martian crust has led a research team to conclude that the Red Planet may have formed somewhat differently. Their geochemical sleuthing, which appeared this week in Nature Geoscience, suggests that beneath the planet’s rocky shell sit two types of Martian material—unmixed relics of the baby planets that came together to form Mars. The researchers teased apart these twin substances based on traces of water,...