EarthDate

The Andean Condor is a giant vulture that lives along South America’s west coast. It’s one of the heaviest flying birds in the world, weighing more than 30 pounds. Yet it can stay aloft for hours at a time. How do condors do it? Efficiency! The condor launches itself from a high peak or cliff, spreads its massive wings—the largest in surface area of any living bird—and soars. It will then ride the...

Gold is malleable, portable, nontoxic, beautiful and rare. Those qualities have made it an excellent currency over the centuries. But there’s another metal with all those properties and more—and it’s much more valuable. It’s called rhodium, part of the platinum group of metals. The name comes from the Greek rhodon, meaning rose, for the rosy color of rhodium compounds. It’s abundant in other parts...

In 1836, Charles Darwin and his colleague Joseph Hooker visited Ascension Island, really just a barren pile of volcanic basalt topped by an old cinder cone, ironically named Green Mountain. There were very few plants, but some soldiers had successfully grown a vegetable garden in the volcanic soil. This gave Hooker a crazy idea. He contacted his father, the director of the botanical garden in Lond...

Fireflies are sometimes called lighting bugs or glowworms. But they’re not flies, bugs or worms—they’re beetles, with a marvelous capability. They move oxygen through a tube in their abdomen to combine it with a special pigment called luciferin to produce bioluminescence, the familiar glow that gives fireflies their name. There are 2,000 species of firefly around the world and 170 in the US. Diffe...

Microscopes, telescopes and lenses. Smartphones, laptops and televisions. Mirrors, windshields and cathedral windows. None would be possible without glass. It’s made of silicon dioxide, or quartz, that’s melted and then cooled so fast that crystals can’t form, which gives glass its most important quality today: transparency. But glass was first valued for the way it breaks. Early humans found natu...

Scientists have a new way to measure rain, or rather, rain intensity. They looked at data from 185 weather stations across the globe, from 1999 to 2014, to determine how much rain fell in how many days. They found that, on average, one twelfth of an area’s rain falls in its single wettest day, one eighth in its wettest 2 days, and half in just 12 days. They decided to standardize this metric—the n...

We’re all familiar with those violent shaking events we call earthquakes. But it may surprise you to know that Earth more often moves without quaking in what’s called a slow or silent slip. It sure surprised scientists: they discovered this just 20 years ago. Earth’s tectonic plates began to move over a billion years ago. Their constant motion has formed, pulled apart, and slowly destroyed contine...

Landslides happen when a slope becomes unstable—because of denuding, from a fire or deforestation; over-steepening, from erosion or mining; overloading, from a reservoir or heavy snowpack; or oversaturation, with rain or melt water. So many things can cause a landslide that they happen in every U.S. state and nearly every country. When the slope gives way, soil can speed downhill at 50 to 100 mile...

The South Pole is the most inhospitable place on Earth—yet, each year, around 50 brave scientists and staff endure the winter there. Outside temperatures approach minus 120 degrees Fahrenheit in constant darkness. And they better hope nothing goes wrong. Because no one can come to help them. The South Pole is 800 miles from the nearest human contact. That’s farther than the International Space Sta...

There’s an Irish saying, “There’s a pot of gold at the end of every rainbow.” But it used to say, “you’re as likely to find a pot of gold as the end of the rainbow.” That’s because if you go looking for its end, the rainbow vanishes. Rainbows occur when water droplets—from rain, mist, waterfalls, even sea spray—hang in the air. When sunlight enters the droplet, some will reflect off the back side...

Herbivores eat plants, and carnivores eat animals that eat plants, to get their energy. Plants and many bacteria create their own energy through photosynthesis, which depends on chlorophyll…which requires nitrogen. As we’ve described in other episodes, most nitrogen on Earth is in the form of N2, the inert nitrogen gas that won’t bond with other compounds, making it useless to plants. So, most pla...

There are no snakes in Ireland. Because, according to legend, St. Patrick expelled them. True, or folk tale? St. Patrick, ironically, wasn’t Irish. Or, named Patrick. He was born Maewyn Succat in 390 AD in Britain, kidnapped by pirates at 16, and held in slavery in Ireland for 6 years. He escaped and joined a monastery in England. Then decided to return to Ireland as a missionary, where he convert...

In the 1800s, scientists found a 400-million-year-old fossil fish they thought could be the missing link between aquatic and land-dwelling creatures. They would have loved to study it, but it had gone extinct with the dinosaurs. Or so they thought. Until 1938, when a museum curator saw a fisherman haul one out of his net in South Africa. She wrote a hasty telegram to her museum. They wrote back: “...

Tornadoes are mysterious. But on this EarthDate, we’ll try to unravel a few of their secrets. You’ve probably heard there’s a “tornado season” that happens in “tornado alley.” Well, not exactly. Tornadoes can happen almost anywhere—North and South America, Australia and New Zealand, South Africa, and the Indian subcontinent, where they’re most deadly due to higher population density. And they can...

700 million years ago Earth froze over completely and stayed that way for millions of years. How did this deep freeze start, and how did it end? We think it went like this: At the time, all of Earth’s land was held in one large continent called Rodinia. As it began to break up, huge areas eroded, pulling carbon dioxide from the air and sequestering it in minerals. With CO2 dropping, the atmosphere...

Sponges may look like plants, but they’re animals—some of the longest-lived on Earth, with a few living more than 10,000 years. They’re also the least evolutionarily advanced creatures on the planet. But new accidental findings may show we’ve underestimated them. Sponges evolved more than 500 million years ago, flourished through Earth’s great extinction events, and have endured ever since. Today...

Penguins have been around a long, long time. They first evolved more than 60 million years ago when the asteroid that wiped out the dinosaurs opened a niche for them. Fossils suggest they were already flightless, but they took to the sea where they became perfectly adapted: Their feathers are coated in oil. Their body is insulated in fat. Their wings are shaped like flippers, making some penguins...

On Super Bowl Sunday, Americans eat 26 million avocados in our guacamole. Annually, we average 8 pounds of avocados per person. A third of the world’s supply comes from Mexico, which is where the avocado developed. It began as a small black fruit called the criollo from the same family of trees that produce bay leaves and cinnamon. The fruit was a favorite of giant herbivores, similar to today’s r...

In 1492, Columbus sailed the ocean blue. But… In 1021, the Vikings landed in Newfoundland. That’s right, we’re now certain that Norse explorers reached North America nearly 500 years before the Spaniards. It happened at L’Anse aux Meadows, in easternmost Canada, where explorers in the 1960s discovered the remains of Viking longhouses. But they didn’t know exactly when they arrived or left. We now...

The 2020 Census counts 331 million people living in the USA. Worldwide there are now almost 8 billion. Which means the United States represents just 4 percent of the total global population. China and India, with nearly 3 billion people combined, make up about a third of total population. Researchers also recently calculated a global biomass census to compute the total weight of all things living...

For 500 years, explorers have looked for a passage above North America, from the Atlantic to the Pacific. With a warming Arctic, they’ve finally got it. Which could have profound impacts on geopolitics. In the 1500s, Spain and Portugal controlled the sea routes to their colonies in the Americas. Northern Europeans, looking for their own way to reach Asia, began searching for a Northwest Passage th...

The Australian bushfires of 2019 produced so much smoke, it entered the stratosphere, 19 miles above Earth! On an earlier episode, we talked about how fires make their own weather. As a column of hot air rises from the flames, it carries smoke into the atmosphere where it forms clouds. Water vapor may condense around smoke particles and rain down to quench the fire. Or lightning may form in the cl...

Before antibiotics, millions died each year of diseases we can easily treat today. If we’re not careful, we may be headed back to those deadly days. In 1928, Alexander Fleming discovered that a fungus, Penicillin rubrum, could kill bacteria. But his fellow doctors wouldn’t listen. It wasn’t until 1943, when he cured a patient dying of meningitis in just one week, that they finally paid attention....

When conditions turn extreme and food and water get scarce, many creatures shut down their metabolism and go into suspended animation. This is much different than sleep. Body temperature drops to near the ambient temperature. Bodily functions slow, with some stopping altogether. This dormancy comes in several varieties: Some species go into daily torpor in the heat of the day. Hummingbirds, for in...

Wooly mammoths lived in Siberia and North America from about 5 million to as recently as 4,000 years ago. They stood the same height as African elephants, up to 11 feet at the shoulder, but with long shaggy coats and much longer tusks. Within one of those tusks, scientists found a remarkable story. Mammoth tusks were just specially developed teeth, which grew new layers every year, from the inside...