Huge thunderstorms, like this one over the Pacific Ocean captured by photographer and pilot Santiago Borja, can penetrate the stratosphere some 18 kilometers up. Scientists are studying whether such “overshoot” storms are injecting synthetic chemicals that harm Earth’s protective ozone layer into the stratosphere.
TOM BOUYER/EXPEDITION 5300
A miner walks along a cliff edge carrying rocks on his back to later grind them up in search of gold. The mining village of La Rinconada, Peru, is the highest settlement in the world at 5100 meters. Scientists are studying residents there to understand the long-term effects of extremely low oxygen levels on the body.
CAVAN IMAGES/ALAMY STOCK PHOTO
A boat drives through an algal bloom in Lake Erie, where excessive nitrogen levels from human activities starve the underwater life and impact human health. There are large-scale changes happening in the nitrogen cycle, and scientists are now looking at how to manage the excess nitrogen for different communities.
ADAM LEWINTER/U.S. ARMY ENGINEER RESEARCH AND DEVELOPMENT CENTER COLD REGIONS RESEARCH & ENGINEERING LABORATORY/REMOTE SENSING/GIS CENTER OF EXPERTISE
Greg Hanlon, of the U.S. Army Corps of Engineers, peers up through a skylight in Greenland’s Helheim Glacier. His team returned to the glacier for another year of fieldwork and data collection to monitor how the mixing of the glacier’s meltwater and ocean water may be speeding up sea level rise.
Sockeye salmon are ready to spawn near a University of Washington research station in Alaska’s Lake Iliamna, where 20% of the salmon in Bristol Bay are produced. Researchers who track their life and migration patterns in the area are battling with what would be the world’s largest gold mine, Pebble Mine, which is planned to sit upstream of the lake.
Gao Caixia, a leading CRISPR scientist, stands among her CRISPR-modified wheat plants inside a grow room in Beijing. Gao hopes her plants will be able to feed more of China’s expanding population.
NASA/JPL-CALTECH/SPACE SCIENCE INSTITUTE/TILMANN DENK
The moon Daphnis makes waves in between Saturn’s rings. This close-up image is just one of the pictures captured during the Cassini spacecraft’s grand finale. During these ring-grazing orbits, scientists got a closer look at the ring structures and five of Saturn’s moons.
This year we celebrated the 150th anniversary of the periodic table. Theodore Gray, co-founder of Wolfram Research in Champaign, Illinois, assembled his own collection of available elements on top of his literal periodic table. His imaginative display shows glowing tubes of the gases in the far-right column and compartments below to store samples safely.
A pro-democracy protester throws a lit Molotov cocktail outside Hong Kong Polytechnic University over the territory’s relationship with China. Officials at several universities fear the clashes will make it harder to recruit students and faculty.
A giant male humpback whale fights for a mate off the coast of Tonga in the Pacific Ocean. Scientists are studying why these animals are big, but not bigger.
JOHN BAZEMORE/AP PHOTO
Nurse K. J. Moore speaks during the public comment portion of a Centers for Disease Control and Prevention vaccine panel in Atlanta. Moore disagrees with a requirement that health care workers receive flu vaccines.
A hill of uncultivated land sits in the middle of an oil palm plantation in West Kalimantan in Indonesia. Conservation scientists have started to work with the palm oil industry to protect the wildlife living there.
AMAZON-IMAGES/ALAMY STOCK PHOTO
A day-old hoatzin chick has claws on its wing, which will be gone by the time it is full grown. This year, scientists detailed how young hoatzin use their claws to climb and move around, raising questions about why the birds lose their claws as adults.
Colorful domesticated potatoes are grown in the fields of the central Andes in Peru. These spuds come from pre-Inca cultures at 3000 to 4500 meters above sea level. Researchers hope that diversifying the modern potato could enable it to better fight off diseases and climate change.
JEN GUYTON/NPL/MINDEN PICTURES
A shy ground pangolin unravels in a national park in Mozambique. These mammals are the world’s most poached animal. Captured for their scales and meat, they are inching closer to extinction.
A young girl sits in the child care unit of Ifanadiana Hospital in Madagascar, where she was treated for severe malnutrition. Researchers are testing a new health care system that could be used across the country.
MATTHEW BENDER/JAMES BARTOLOZZI
Physicist Danielle Bassett of the University of Pennsylvania stands near her lab’s representation of the brain’s structural connections, which was made from MRI data. Bassett is a pioneer in using physics and math to study the networks in the human brain.
DAN SAZER/JEFF FITLOW/JORDAN MILLER
A focus-stacked picture of a tiny, 3D-printed alveolus, or artificial lung. Scientists designed this breathing apparatus to better study bioengineered cell tissues.
The Milky Way shines above the Australian Square Kilometre Array Pathfinder. There, scientists have used the 36 dishes to trace a radio pulse known as a fast radio burst to its source in a far-away galaxy.