EarthDate

The most extreme, most inhospitable lands on Earth are the McMurdo Dry Valleys, near the coast of Antarctica, just inland from the McMurdo science base. We normally think of Antarctica as covered in ice. But the dry valleys are surrounded by mountains, which block precipitation. What little water does accumulate is blown away by the constant winds. And yet, there is life. From December to March, t...

When plastics were introduced, they replaced glass, metal, paper and wood in many applications. That’s because plastic is a miracle. It’s cheap, light, can be formed into millions of products, and is incredibly durable. But these big benefits have led to a very big problem. Plastic pollution is now everywhere. And because it’s so durable, it’s not going away. Plastic pollution starts with us, most...

Gold has been valued by humans for at least 7,000 years. The earliest gold items were found in Bulgaria, from the 5th millennium BC. The first mines were likely in the ancient African kingdom of Nubia. Egyptians created great wealth, and great art, from gold. Gold is valuable because it’s so unusual. It’s very dense, even denser than lead. It’s very durable, yet also very soft. It’s the most malle...

One night in the mid-1800s, a naturalist in a boat saw something mysterious. The surface water was teeming with daphnia, zooplankton more commonly known as ‘sea fleas.’ The next morning, they had disappeared. The next night, they were there again. Where did they come from? Where did they go? For a century, this was a mystery. Then navy ships, using sonar to track submarines, found that the deep oc...

On the island of Flores, in Indonesia, a team of anthropologists made a discovery so surprising, they kept it a secret for a year. In a cave called Liang Bua, they had uncovered 100 skeletal fragments of about 14 individuals – so small, that at first, they thought they might be the remains of children. But more investigation showed wisdom teeth and wear on bones that definitively marked these skel...

You may have seen sunscreens that claim to be “reef safe.” Which may have made you wonder, are sunscreens dangerous to coral? If so, could they be dangerous to me? Sunscreens come in two basic types. Inorganic, which are mineral based, using white zinc or titanium oxides to physically block the sun’s rays. And organic, using oxybenzone or octinoxate to absorb UV rays and turn them into heat. You’d...

Mosses are small but mighty. We don’t think much about them, since they grow so close to the ground. But there are an estimated 22,000 species of moss, living on every continent including Antarctica, covering 2% of Earth’s surface. That’s the size of Canada! The soil under mosses globally can store 6 billion tons more carbon than bare soil. That’s more than the U.S. emits each year. After lichen,...

Amazingly, the structure of most living things, and many other things as well, conforms to one sequence of numbers. It was described in the 1200s by Italian mathematician Leonardo Pisano, also called Fibonacci, working from earlier Indian ideas. The Fibonacci Sequence is 1, 1, 2, 3, 5, 8, 13 and onward – where the first two numbers, one and one, add up the next number, two. The next two numbers, o...

What’s the world’s most dangerous animal? Sharks? Nope, they bite only 70 people a year, with just six fatalities. Poisonous snakes? They kill about 50,000. But far and away the most dangerous is the mosquito. It kills a million people a year, and sickens 250 million more! But we may be able to stop it, with an even tinier creature. There are 3,000 species of mosquito. Different ones can carry mal...

Thought to have been extinct for over 2 million years, a cluster of Wollemi pine was discovered by hikers in a secluded canyon outside of Sydney, Australia in 1994. Guarding this area from humans and fire along with cultivation and conservation efforts by botanical gardens have safeguarded this unique species. Now, advances in decoding the Wollemi pine genome may provide the secret to successfully...

Grand Teton National Park contains North America’s youngest mountain range: the towering “Tetons.” While the range formed by extension along a tectonically simple “normal” fault, the Teton Fault is unique because it has moved nearly 33,000 ft (10 km) in just ten million years. Preserving astounding natural beauty and a human history stretching back at least 11,000 years, the national park was firs...

Sometime long ago, a small meteorite crashed into the sands of the Sahara. In 2011, scientists discovered it and dubbed it NWA 7034 – nickname: Black Beauty. It was soon recognized as the rarest meteorite on Earth. Black Beauty came from Mars. Scientists know that because oxygen isotopes trapped within it match those in the Martian atmosphere. Because that atmosphere is so thin, Mars is not well p...

The blast was over a thousand times stronger than Hiroshima, heard 700 miles away. It killed 57 people and countless animals. This was the eruption of Mount St. Helens 45 years ago in Washington, the deadliest, most damaging volcanic event in modern US history. Surprisingly, in America today there are 169 active volcanoes. Most are in Alaska. A few in Hawaii have small eruptions regularly. There a...

Snowpack provides our water, especially in the American West. And new research shows wildfires may be affecting it. Snow accumulates in the mountains in winter, then melts in spring to fill rivers. As we’ve discussed in prior EarthDates, that runoff is critical to water supplies, for irrigation, fisheries and cities. Earlier melting, due to more winter rain, has brought spring floods. This can mea...

We’ve all seen geodes, and marveled at their beautiful crystal interiors, but do you know how they form? Geodes occur mostly in lava and sedimentary rocks. In molten lava, gas bubbles and lava tubes form, some quite large. They become voids as the rock hardens, and can fill with mineral-rich fluids. Over many years, minerals precipitate out, and crystals line the void. As more fluids seep in, more...

The Wallace Line, a boundary separating the unique species of Australia from those of Southeast Asia, has long fascinated scientists. Exploring the influence of plate tectonics, glacial periods, and geographic isolation may hold the answer to this mystery.

Ancient heating and cooling systems operated without electricity, which could today provide solutions for climate control in places without electricity or where outages have become more common. Wind towers that capture wind or thick walls can work to passively cool or insulate buildings. Southern facing windows with shading devices, and adobe construction, can keep homes warm or cool depending on...

Oxygen. Without it, life on Earth would look very different. Because only plants and a few types of microorganisms can live without it. Fortunately, plants originated 3.5 billion years ago. They inhaled so much carbon dioxide and exhaled so much oxygen that they changed Earth’s atmosphere. With more oxygen in the air, Earth could sustain animal life -- which would eventually become us. Those first...

Two of the most important geologic features of our planet, that shape our oceans and continents, are Earth’s two types of crusts – oceanic and continental. Both types float on Earth’s asthenosphere – its semi-molten mantle. Oceanic crust is thin, averaging just 5 miles thick. It rises out of the mantle at mid-oceanic ridges and sinks below continents at subduction zones. It’s constantly being recy...

For 99% of hominin history, we were living in the Stone Age. It began some 3 million years ago, followed much later by the Bronze and Iron Ages, at just 10,000 and 5,000 years ago. Hominins have used wood throughout those ages. For all that time, you could say we’ve been in a Wood Age -- though scientists never officially named one. Wooden artifacts don’t often turn up in the archaeological record...

Antarctica is a continent of extremes and superlatives. It’s the coldest continent, with Earth’s lowest recorded temperature of 130 below zero Fahrenheit. It’s the driest continent, with just 6 inches of precipitation a year. It’s the windiest continent, with gusts up to 200 miles an hour. Surprisingly, it’s the highest continent, with an average altitude of 8,200 feet, largely due to ice sheets u...

Like the legendary unicorn it resembles, the narwhal is an enigma. It lives only in Arctic waters, in a frozen seascape far from civilization, making it hard to study and therefore not well known to science. For instance, we don’t know what it does with its most distinctive feature. We do know that its 6- to 10-foot tusk is actually a single tooth, which grows through its lip and continues growing...

Anyone who’s been in an airplane has heard that constant roar of flight. That’s partly the engines—but the noise comes more from air rushing over the wings. Anyone who’s seen an owl fly… hasn’t heard anything. Because unlike an airplane, owls fly almost silently. How do they do this? Aeronautical engineers have examined owl wings and found several features working together: The leading edge of the...

Water is heavy. When we move enough of it, it can change the tilt of Earth’s axis. It’s that axial tilt that creates our seasons. And the tilt is always changing, due to changes in Earth’s gravity. Natural phenomena like earthquakes and volcanoes can redistribute the weight of continents, affecting Earth’s gravity. But so can the movement of water. Researchers recognized that water melting out of...

Many animals hibernate, but only the wood frog can freeze solid in winter—its heart and brain stopping completely—then thaw and come back to life in the spring. Its process to do this is fascinating … and could one day save human lives. The danger with freezing is ice. If water freezes within a cell, sharp ice crystals will puncture or rupture cell walls and kill the cell, which normally kills the...