On the Cover: Starkly beautiful, Antarctica is the coldest, driest, windiest continent on Earth. Thanks to the Antarctic Treaty, it is also a protected ecozone that supports ongoing scientific research by more than 4,000 scientists from around the world. Here, otherworldly towers of ice appear (about 9 meters, or 30 feet, high) to march up the slopes of Mount Erebus, Antarctica’s only active volcano. Some scientists speculate that geologically active, watery moons such as Europa and Enceladus might also sport features like these.
6 Wonderfully Habitable Worlds? Franck Marchis expounds on what we know—and don't know—about the TRAPPIST-1 planetary system.
15 The Fading Fortunes of Mars: Casey Dreier observes the rise and potential fall of NASA's Mars program.
20 A Planetary Defense Update: Bruce Betts reports on the work of our Shoemaker Grant winners, and an upcoming planetary defense conference.
23 Welcome to the New Uncertainty: Casey Dreier wonders about NASA's future under a new administration.
4 Volunteer Spotlight Curiosity unites us all.
4 Your Place in Space Bill Nye on a very busy spring.
22 What's Up? Planets in the morning and evening skies.
24 Snapshots from Space Emily Lakdawalla shows off a tiny moonlet inside Saturn's rings.