EarthDate

For millennia, people have been drawn to volcanoes. Why? Because before they arrived, the volcanoes had erupted. Their lava, ash and debris covered the surrounding area, making for fertile farmlands that drew settlers … who may not have recognized that the volcanoes could erupt again. And that’s just what happened around Italy’s Mount Vesuvius. Long before the Romans, people had come to farm there...

Last EarthDate, we talked about the eruption of Mount Vesuvius, which completely covered Pompeii in ash. Within a century, the city was forgotten. Until the 1500s, when an architect dug into a room. It had once been a brothel, with explicit frescoes on the wall. Considering them inappropriate, he buried them again. In the 1700s, artifacts were discovered in a vineyard in the volcanic soil above th...

Every 11 years, the Sun cycles from solar minimum to solar maximum, as we discussed in a prior EarthDate. And we’ve just entered another solar maximum, where the Sun emits many more charged particles in a faster, stronger solar wind moving toward Earth. You might experience it in disrupted GPS or cellular signals. But you can see it in the night sky. Specifically, in the aurora borealis, the famou...

You might not think a river can burn. But in 1969, the Cuyahoga River that runs through Cleveland caught fire. The Cuyahoga was the most polluted river in the country, so fouled with industrial waste and sewage that it was completely devoid of life when a spark from a passing freight train ignited an oil slick that covered the water. The river had burned at least 10 times in the previous 100 years...

One of our greatest scientists was given an aristocratic title by Parliament. But he began life simply, as a math teacher’s son. William Thomson was born in Belfast, Ireland. His father moved the family to Glasgow for a job at the university. He started William in classes at 10 years old. Immediately, his talent began to shine. In his teens, he published three papers on the relationship between he...

Drinking salt water is poisonous to humans. It’s four times saltier than our blood, so our kidneys pull water from our tissues to try to balance the seawater, which could lead to dehydration or death. Whales and dolphins, seals and walruses are all mammals, and they need fresh water too. But they live in salt water. So what do they drink? Nothing! Their digestive systems are superefficient at pull...

If left unprotected, something made of iron will dissolve into dust. That’s because of rust. Some metals, like gold and platinum, are naturally stable and keep their shiny appearance. Other metals like aluminum, copper and silver develop patina or tarnish that protects the raw metal beneath. Iron is different. It’s the most abundant element on Earth, followed by oxygen—together they make up over 6...

The world’s most successful research submarine, Alvin, has completed over 5,000 dives in its 60-year career. Its first mission, in 1966, was to search for—and find—a hydrogen bomb that had fallen into the deep ocean. Two years later, cables snapped while Alvin was being lifted aboard its tender ship, and it sunk to the bottom of the Atlantic … where the sub itself had to be retrieved. It has been...

Native American legend says the Creator, when done forming Earth, threw all the leftover rocks into a pile in West Texas—a jumble of geology that today we call Big Bend. It gets that name because it sits in a 200-mile-long curve in the Rio Grande River that separates Texas and Mexico. Big Bend is now a nearly million-acre national park—with a protected area twice as large on the Mexican side of th...

Big Bend is one of the largest, most remote and least visited national parks in the U.S. It’s a land of great diversity. More than a mile of elevation change. More than 100 degrees Fahrenheit of temperature fluctuation annually. Diverse topography—deserts, mountains, canyons, rivers and springs—with different life in each ecozone. And because of that, more ecological diversity than any other natio...

It’s going to be a very noisy summer! This year, more cicadas will fill the air with—song?—than any summer since 1803. Cicadas evolved 150 million years ago, and 3,000 species now live on nearly every continent. These are called “annual” cicadas. They live a few years underground, then crawl up a tree and shed their crusty “underground” skin for a final molt into their winged adult form.  They liv...

If you were to design the perfect industrial material, what would it be like? You’d want it to be strong and lightweight. Easy to form into different shapes. You’d like it to be resistant to corrosion. And to heat. Ideally, you could easily combine it with other materials for more uses. And re-uses. It would be best if all these qualities came in something cheap and abundant. And in fact, they do....

Leonardo da Vinci was one of our most brilliant thinkers. He’s known as an inventor, scientist, mathematician, architect, sculptor and, of course, painter of the most famous portrait in the world, the Mona Lisa. But unless you’re also a painter, you probably haven’t heard of Leonardo’s Rule of Trees. Intent to paint them realistically, he carefully analyzed trees and recognized a pattern, which he...

In 1933, Hungarian explorer László Almásy set out across the Sahara in search of a legendary lost city. What he discovered was far more magical and, at first, completely unbelievable. In a remote ravine, Almásy found a shallow cave. Inside he saw cave paintings of human figures with outstretched arms and legs. They appeared to be flying. But no, Almásy realized, they were swimming—in the Sahara! O...

What if Earth didn’t have a moon? Well, nearly everything about our home planet would be different—so much, we’d hardly recognize it. Our Moon is a quarter the size of Earth, far bigger than most planets’ moons. Scientists think it formed when a smaller planet crashed into Earth 4 billion years ago, knocking off a chunk that eventually became our Moon. Its large size is key to its dramatic effects...

Millions of miles from Earth, the fastest object that humans have ever built is circling the Sun at 430,000 miles per hour, and nearer than any spacecraft has ever dared go. It’s the Parker space probe, and NASA sent it there in 2018 with a mission: to study solar activity. That’s because, in 2024, the Sun is predicted to reach its next solar maximum. It happens when the Sun’s poles flip and its m...

The stegosaurus is known for its unusual features: rows of large, bony plates along its back, spikes on its tail and a cranium so small that early paleontologists thought there must be another brain hidden elsewhere, like in a nerve bundle at the base of the dinosaur’s powerful tail. But it was the purpose of those plates that really baffled scientists—a mystery they’ve been trying to solve for mo...

“Campi Flegrei” in Italian means “fiery fields.” That may not sound like a place you’d want to live, but 360,000 Italians do. Italy is the only country in Europe with active volcanoes on land. The “fiery fields,” just west of Naples, are actually a caldera—the depression left when a volcano erupts and collapses. At the center of the caldera is the Pozzuoli Bay. The coast around it has been densely...

Almost 400 million years ago, our ancestors slowly emerged from the sea to breathe air and populate the land. It may surprise you to know there’s another species making that same transition right now. It’s the mudskipper, a 4- to 12-inch fish that looks like a frog with only front legs. It has a large frog-like head and smooth, green and brown skin dappled with spots. The mudskipper lives in tropi...

In the 1960s, during the Cold War, the U.S. built an Arctic research center in Greenland and called it Camp Century. Except it was actually a secret military operation—code name: Project Iceworm. It was intended to drill a network of nuclear missile launch silos in the Greenland Ice Sheet, designed to survive a Russian ‘first strike.’ The first people there were researchers, to test the ice for su...

When we think of pollination, we usually think of bees, bats or other flying foragers. They visit male flowers to collect nectar and get covered in sticky pollen, which they carry to female flowers, in search for more nectar. Marine plants also reproduce with pollen, but scientists thought water movement carried it from one plant to another. Then researchers discovered what they called “the bees o...

A total eclipse of the Sun is a special occurrence. The last time that the Sun and Moon lined up perfectly for a total eclipse traversing the U.S. was in 2017; another one is due on April 8, 2024, crossing the country from Texas to Maine. While millions of Americans gaze at the sky in wonder, scientists will be hard at work. Because a total eclipse—by blocking the Sun itself—gives us the rare chan...

The most important number in the universe is arguably … pi. Why? Because it defines circles, spheres and wave motion from atomic to galactic scales. Pi is the ratio of a circle’s diameter to its circumference. If the diameter is 1, the circumference is pi. And pi, you may remember, is 3.1415926535 … etcetera, going on forever and never repeating. It was first recognized 4,000 years ago, and since...

We often hear that sea level is rising, but less often that cities are sinking—which may put them in more jeopardy. This may be caused by land rebounding from the last ice age, when it was covered by ice sheets. While some areas spring upward, others that were pushed upward around the periphery of ice sheets are slowly sinking. Or, Earth's surface may rise or fall when a fault slips, or tectonic p...

Remember the movie Jurassic Park? Or every time you’ve seen a reconstruction of a T. rex in a museum? Probably the image that sticks with you is the exposed daggers of fearsome teeth. Well, some Canadian grad students may have proven that image wrong. They discovered something rather elemental: T. rex teeth have very thin enamel. Even thinner than the enamel on mammal teeth. But early paleontologi...