March 25: A penumbral eclipse will be visible across much of the Western and Eastern Hemispheres.

March 25: A penumbral eclipse will be visible across much of the Western and Eastern Hemispheres.

April 21: Comet Pons-Brooks makes its closest approach to the sun.

Sept. 17-18: A partial lunar eclipse will be visible in the Western Hemisphere.

Oct. 12-13: A newly discovered comet makes its closest approach to Earth.

Morning Person? You Might Have Neanderthal Genes to Thank.

Hundreds of genetic variants carried by Neanderthals and Denisovans are shared by people who like to get up early.

Exactly How Much Life Is on Earth?

According to a new study, living cells outnumber stars in the universe, highlighting the deep, underrated link between geophysics and biology.

Watch ‘Sea Fireflies’ Make Underwater Fireworks as They Seek Mates

Tiny crustaceans the size of sand grains sneeze up packets of glowing mucus to impress potential partners.

Could a Drug Give Your Pet More Dog Years?

Longevity drugs for our canine companions are moving closer to reality. They also raise questions about what it might mean to succeed.

Why Warblers Flock to Wealthier Neighborhoods

In the unequal distribution of birds and other species, ecologists are tracing the impact of bigoted urban policies adopted decades ago.

A Giant Leap for the Leap Second. Is Humankind Ready?

A top scientist has proposed a new way to reconcile the two different ways that our clocks keep time. Meet — wait for it — the leap minute.

Fruit Flies Are Invading Los Angeles. The Solution? More Fruit Flies.

The Mediterranean fruit fly lays eggs that hatch into maggots inside fruit. Officials plan to halt population growth by dropping millions of sterile male flies over the affected region.

Now Showing, an Ancient Spell Book for the Dead

An exhibition at the Getty Museum reveals the Egyptian Book of the Dead, long relegated to a dark vault, in the light of day.

6 Great Space Images in October

An eclipse's shadow from space, India's astronaut capsule and a confused space telescope.

These Amphibians Have a Taste for Their Mom’s Skin

Caecilians are the first amphibians known to pass on their microbiomes to their offspring.

Inside a High-Security Virus Lab

High-security labs, like this one at Penn State, are at the center of a debate over research that alters viruses to make them more dangerous.

Deep in the Amazon, some towns had better eclipse fortune than others.

On a beach in Brazil, a shadowy path of wonder reaches its conclusion.

Your Next Eclipse Isn’t That Far Off, and It Could Be Even Better

Saturday’s eclipse will be followed by another in April that will cross the other end of the United States.

A Solar Eclipse Shines Light on Traditions That Still Matter Today

Among Indigenous peoples of the Americas, from Navajo Nation down to the rainforests of Brazil, events like the annular eclipse on Saturday have important and distinctive cultural meanings.

Why the “Mother of the Atomic Bomb” Never Won a Nobel Prize

Lise Meitner developed the theory of nuclear fission, the process that enabled the atomic bomb. But her identity — Jewish and a woman — barred her from sharing credit for the discovery, newly translated letters show.

Evelyn Fox Keller, Who Turned a Feminist Lens on Science, Dies at 87

Trained as a physicist and biologist, she argued that science had become gendered, with a narrow masculine framework that distorted inquiry.

To Knock an Elephant Off Balance, Bring Out a Giant Blindfold

Elephants rely on visual cues to maintain consistent timing of their strides, a new study suggests.

In Peru, a Fossil-Rich Desert Faces Unruly Development

The Ocucaje Desert, where paleontologists recently unearthed the ancient skeleton of the world’s heaviest animal, is being overtaken by human settlement.

An Ancient Whale Named for King Tut, but Moby-Dinky in Size

Paleontologists in Egypt announced the discovery of Tutcetus rayanensis, an eight-foot-long leviathan that lived 41 million years ago.

How to Watch NASA Bring Asteroid Samples Home From Space

A seven-year mission might end on Sunday as scientists try to drop off a sample of rock from Bennu, an asteroid that might hold clues about the origins of our solar system and life.

India’s Moon Lander Misses Wake-Up Call After Successful Mission

The Chandrayaan-3 mission did what it set out to do, but its lander and rover could not be roused after entering the cold lunar darkness two weeks ago.

This Tiny Parasitic Wasp Can Drill Through Plastic

In experiments under his microscope at home, a teenage researcher discovered a very unusual talent in a species of tiny insect that usually lays eggs on the inside of a tough plant growth.

A Vanishing Nomadic Clan, With a Songlike Language All Their Own

New genetic research confirms the oral history of a small group of nomadic people living in Indonesia’s rainforest.

Northern Lights Shine in Midwestern Skies

The colorful display from Aurora Borealis was visible from parts of the U.S.

What We Know About Children and Opioids

A 1-year-old died and three other children fell ill at a New York day care, and the authorities blamed opioids. Children are significantly more vulnerable to drugs because of their small bodies.

Some Whales May Have Been Wiped Out by Medieval Europeans

A study of hundreds of specimens from European archaeological digs found two species of whales that are no longer present in the continent’s waters.

NASA Announces New Job: U.F.O. Research Director

The role was created in response to the recommendations of a report that found the agency could do more to collect and interpret data on unidentified anomalous phenomena.