An aerial photo shows the remains of a delta where a water source once fed an ancient lake at the Jezero crater on Mars. Credit: NASA/JPL-Caltech/ASUGround-penetrating radar reveals eons of environmental changes, offers hope that soil samples hold traces of life.Ground-penetrating radar onboard NASA’s Mars Perseverance rover has confirmed that the Jezero crater, formed by an ancient meteor impact just north of the Martian equator, once harbored a vast lake and river delta.Over eons, sediment dep...