Our Planet

An image of Augustine erupting on January 13, 2006, from about 50 miles away from the volcano.

Volcanic Lightning

As sparks flew during the eruption of Mount St. Augustine in Alaska, scientists made some new discoveries

The ozone hole over Antarctica is recovering. Can the lessons be applied to today's climate crisis?

Ahead in the Clouds

Susan Solomon helped patch the ozone hole. Now, as a leader of a major United Nations report—out this month—she's going after global warming

None

Top 10 Polluted Cities

Jeweler Harry Winston donated the famous Hope Diamond—the largest-known deep blue diamond in the world—to the Smithsonian Institution in 1958. It arrived in a plain brown package by registered mail, insured for one million dollars. Surrounded by 16 white pear-shaped and cushion-cut diamonds and hanging from a chain with 45 diamonds, the rare gem attracts 6 million visitors a year to the Natural History Museum.

Diamonds Unearthed

In the final installment of this three-part series, diamond expert Jeffrey Post discusses the histories behind the Smithsonian collection

Jeweler Harry Winston donated the famous Hope Diamond—the largest-known deep blue diamond in the world—to the Smithsonian Institution in 1958. It arrived in a plain brown package by registered mail, insured for one million dollars. Surrounded by 16 white pear-shaped and cushion-cut diamonds and hanging from a chain with 45 diamonds, the rare gem attracts 6 million visitors a year to the Natural History Museum.

Diamonds Unearthed

Smithsonian diamond expert Jeffrey Post discusses conflict diamonds, colored diamonds and synthetic gems grown in the lab

Lake Champlain's Isle La Motte is rich in marine fossils, some of which are 450 million years old.

Paleozoic Vermont

What's the world's oldest communal ocean reef doing in the Green Mountain State?

Though sundials have been around 3,000 years, William Andrewes (indicating the lateness of the hour in his garden in Concord, Massachusetts) is perhaps the first to build one showing the time in multiple places simultaneously.

The Shadow Knows

Why a leading expert on the history of timekeeping set out to create a sundial unlike anything the world has ever seen

Jeweler Harry Winston donated the famous Hope Diamond—the largest-known deep blue diamond in the world—to the Smithsonian Institution in 1958. It arrived in a plain brown package by registered mail, insured for one million dollars. Surrounded by 16 white pear-shaped and cushion-cut diamonds and hanging from a chain with 45 diamonds, the rare gem attracts 6 million visitors a year to the Natural History Museum.

Diamonds Unearthed

In the first installment of a multi-part series, Smithsonian diamond expert Jeffrey Post explains how the rare crystals form

Light shining through the ice turns a cave's roof (above, Amy Rarig, age 17) an eerie blue.

The "Girls on Ice" Share Their Experiences in the Field

Once extracted, labeled and bundled, the cores are carefully airlifted to the safety of the lab. Only there will the ice's true secrets be revealed.

Glaciologist Erin Pettit Reports from the Field

None

Frozen in Time

Glaciers in the Pacific Northwest have recorded hundreds of years of climate history, helping researchers plot how quickly the planet is warming

The students (including Molly Holleran, age 17) practiced self- arrest—stopping a fall on a slope using an ice ax.

Glaciologist Puts Her Girls on Ice

None

Neanderthal Man

Svante Pääbo has probed the DNA of Egyptian mummies and animals. Now he hopes to decode the DNA of our evolutionary cousins

None

Wild Things: Life as We Know It

Bumblebees, elephants and endless summer

Christopher Landsea and Stanley Goldenberg (above, aboard a NOAA jet) say there's not enough data to blame recent powerful hurricanes on global warming. Instead, they say, other air and sea conditions are responsible.

Storm Warnings

Is global warming to blame for the intensity of recent Atlantic hurricanes? While experts debate that question, they agree that tempests are headed our way

Madeleine Nash

Interview with J. Madeleine Nash, Author of "Storm Warnings"

Nash, a science reporter, discusses her most thrilling weather experience, and her fascination with the scariest forces of nature

A stone statue of Hatshepsut

Climate Change

Time often shapes perceptions

Nature Works has figured out how to make plastic out of corn.

Corn Plastic to the Rescue

Wal-Mart and others are going green with "biodegradable" packaging made from corn. But is this really the answer to America's throwaway culture?

Ferns and bamboo grow densely where ancient trails (walked by Josh Rapp, to the left of Miles Silman) allow more light to penetrate the canopy.

Uphill Battle

As the climate warms in the cloud forests of the Andes, plants and animals must climb to higher, cooler elevations or die

Building Sustainable Cities

The 227-city U.S. Mayors Climate Protection Agreement is just the beginning.

Page 91 of 99