Bob Zimmerman surveys new discoveries: astronomers have detected a helium atmosphere on a terrestrial exoplanet located 48 light-years away in its star's habitable zone. Closer to home, archival data from Pluto reveals massive landslides, proving the dwarf planet is geologically active rather than dormant. Meanwhile, new images of Valles Marineris on Mars illustrate the canyon's staggering scale, with depths equivalent to the height of Mount McKinley. These discoveries emphasize that planetary bodies across our solar system are dynamic and evolving. (12)
OCTOBER 1958
