New Horizons data reveal Pluto’s first six confirmed landslides along steep crater rims. More

The organic molecules could come from life or from ordinary chemistry — only samples returned to Earth can settle it. More

Editor in chief Nancy Shute discusses NASA’s rocky relationship with Mars exploration. More

Viking 1 kicked off the search for Martian life 50 years ago. Now NASA’s shifting priorities are putting the quest in limbo. More

Over more than a decade at Mars, the orbiter revealed how the solar wind strips away the planet’s atmosphere — and why the world lost its water. More