EarthDate

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EarthDate is a short-format weekly audio program delivering concise, science-based stories about the Earth: its geology, environments, and the processes that shape our planet over deep time and today. Beginning in 2026, EarthDate is managed by Switch Energy Alliance and hosted by SEA's founder Dr. Scott W. Tinker. Together, we explore earth systems, natural resources, and their relevance to everyday life, with a focus on clear, accessible science education for broad audiences. EarthDate is written and directed by Emmy-winning filmmaker Harry Lynch, and researched by Lynn Kistler. We search for captivating stories to remind listeners that science can enlighten, educate and entertain.

  1. 19H AGO

    Carlsbad Caverns

    Carlsbad Caverns National Park is a very rare place. Its main room is the largest cave chamber in North America, covering more than eight acres. And its cave formations are unsurpassed anywhere. It’s also rare because it was created not by carbonic acid percolating down through the soil but by sulfuric acid coming up from below. Around 20 million years ago, hydrogen sulfide gas began to migrate underground from oil deposits in the Permian Basin of Texas, toward the exposed fossilized reefs near what is now Carlsbad, New Mexico. There, the hydrogen sulfide gas rose to meet the water table. It combined with oxygen to create sulfuric acid and began to dissolve the limestone that forms the Permian reef. Over the ages, as the water table rose and fell, the sulfuric acid worked on shallower and deeper layers, creating hundreds of caverns, some thousands of feet below ground. Around a million years ago, erosion connected the caves to the surface. Mineral-enriched water began to trickle in and, drop by drop, over millennia, formed spectacular crystal formations of calcite, aragonite, and gypsum. Seven thousand five hundred years ago the area began to dry up and the cave formations stopped growing. But they’re preserved there today in all their glory—waiting for you to make the trip to Carlsbad Caverns, to see some of the most stunning geology in the world.

    2 min

  2. 19H AGO

    Dinosaurs Run Hot and Cold

    When dinosaurs were first discovered, scientists thought they must have been cold-blooded like the lizards they resembled. Later, they realized that some dinosaurs are related to modern birds—which have the highest metabolic rate in the animal kingdom. Could dinosaurs, too, have been warm-blooded? New research reveals the answer is: both. So-called “cold-blooded” creatures, or ectotherms, are confined mostly to mild climates. They’re more sedentary but require less food and oxygen to survive. Warm-blooded creatures, or endotherms, can thrive in and migrate to diverse climates—but expend much more energy to maintain constant body temperatures. All creatures take in oxygen, and new research shows that the waste products of processing that oxygen—different in warm- and cold-blooded animals—are durable enough to be found in fossils. Molecular analysis of dinosaur fossils suggests an evolutionary break, with cold-blooded, slow-moving herbivores, like Stegosaurus, on one branch, and warm-blooded, highly mobile predators, like Velociraptors, on another. Larger dinosaurs like Brontosaurus and Tyrannosaurus also had high metabolic rates, but not as high as the ravenous Velociraptors. These findings indicate that dinosaurs evolved different metabolisms and body temperatures for different environmental niches—just as today’s animals have.

    2 min

  3. 19H AGO

    The Measure of a Meter

    In the 1700’s, there was no standard of measurement. Every village had its own unit. By some estimates, there were 250,000 different units in France alone. This made commerce and mapmaking so difficult that the French government created a special bureau to standardize things. And they decided to create the meter—which they defined as one ten-millionth the distance from the equator to the North Pole. The problem was they had no way to measure that. So, they made a painstaking, seven-year-long survey of the exact distance between Dunkirk and Barcelona and used the latitudes of those two cities to calculate the distance from equator to pole—which took another year. They divided that appropriately, then cast a platinum bar of that exact length, to create the meter standard. Thirty copies were sent around the world as the basis for the metric system. The bureau created a system of prefixes to denote multiples and divisions of the meter. A thousand meters is a kilometer. One-thousandth of a meter is a millimeter. Modern computers, telescopes and microscopes have required ever larger, and smaller, increments—we’re now up to quettameters, which is a thousand times the diameter of the universe! As our scientific instruments get ever more capable, we’ll need more terms for an ever expanding, and shrinking, metric system.

    2 min

  4. 1D AGO

    Gateway to Hell

    There’s a place in Siberia that the locals call “The Gateway to Hell.” Technically, it’s a retrogressive thaw megaslump. In plain English, a crater melted into the permafrost. In fact, it’s the largest permafrost melt in the world. It began 60 years ago, when the Russians clear-cut a strip of Siberian forest. This exposed the soil to the summer sun, which began to melt a crater that’s now a half mile wide and 300 feet deep—and still growing. This is important for two reasons. First, the crater has exposed 650,000 years of previously hidden sediment. In winter, when the soil is frozen and stable, scientists can enter the crater to recover specimens of extinct animals and to study how cycles of forestation and changing climate have impacted the area over millennia. Second, in summer, when the permafrost is melting, scientists are able to measure the air above the crater. As the organic material thaws, it’s consumed by microbes, which produce CO2 and methane. The crater produces both of these greenhouse gases at twice the rate of the surrounding area. Forest fires have exposed other areas of Siberian soil to the sun. And summer temperatures are rising. Both are melting more permafrost. The Gateway to Hell provides scientists a laboratory to study that melting, to see how it may affect the local landscape, and global climate, in the future.

    2 min

  5. 1D AGO

    Iconic Cacti

    Cacti are native to the Americas and first evolved 30 million years ago—which sounds like a long time—but they’re hundreds of millions of years younger than most other types of plants. They’re specially adapted to dry environments, having transformed their trunks into thick, green, water-storing tissue and their leaves into spines. Cacti grow from half an inch to more than 60 feet in height and range from Patagonia to Canada. They draw in CO2 at night to fuel photosynthesis during the day, then close their pores as temperatures rise to avoid evaporation. Perhaps the most iconic cactus is the giant saguaro. It’s become a symbol of the American West but grows mainly in Arizona. And very slowly. It takes 10 years to reach an inch tall. Seventy to reach six feet. By the time it’s 200, it has reached its full height of 40 plus feet. Along with a tap root to hold it up, saguaros, like most cacti, have a broad shallow root system, just a few inches below the surface. An adult saguaro can use this to suck up 200 gallons of water during a single desert rain storm. That might make them sound like a good water source, but cacti produce acids and alkaloids to protect themselves; drinking their stored water can make you sick. The fruits of all cacti, however, are edible. But most are prickly, and many taste bad. The cactus has evolved to be as tough as its environment.

    2 min

  6. 2D AGO

    Easter Island Egg Hunt

    Easter Island has little to do with Easter—but new research shows it did once have a very impressive egg hunt. More than a thousand years ago, Polynesians crossed thousands of miles of ocean to reach one of the most remote islands on the planet. They called it Rapa Nui and built a community there. Three hundred years ago, a Dutch captain arrived on Easter day and gave the island its Western name. Little did he know that, for centuries, the Rapa Nuans had worshipped migrating birds for their freedom to fly away to distant lands—and had practiced an important and sometimes deadly ceremony each year, upon the arrival of the sooty terns. Young, fit Rapa Nuans would swim the shark-infested waters to Motu Nui, a rocky islet where the terns nested, to harvest an egg. They’d put it in a special headband carrier, then swim the watery gauntlet back to Rapa Nui, where they would climb a thousand-foot sea cliff, careful with every foot- and handhold not to break the egg. The first egg hunter to arrive at the top, with his prize intact, would present it to an important elder in his village, who would be crowned Tangata-Manu, the bird man. His tribe would rule Rapa Nui for the next year. Later, upon the bird man’s death, the islanders would carve a moai, one of their famous mega-statues, in his image. This makes our Easter egg hunts look, well, like child’s play.

    2 min

  7. 2D AGO

    Springtime Impact Apocalypse

    Some paleontologists have recently put forth a controversial idea—that they’ve found a place where the time of year the dinosaurs died is captured precisely in the fossil record. It’s called Tanis, in North Dakota. But it was once the northern end of an inland sea. 66 million years ago, when the Chicxulub asteroid struck the Yucatan Peninsula, it instantly wiped out all life within 1,000 miles. But Tanis is nearly 2,000 miles away—what happened here? Glass spherules, made of quartz, rained down from the heated atmosphere. Shock waves from the huge earthquake caused by the asteroid sloshed the inland sea, in waves up to 30 feet high. Fish died with spherules caught in their gills. Schools of them were found preserved in rocks, with open mouths suggesting death by suffocation. Their bony plates show they had just begun the rapid growth of spring but had not reached the maximum growth of summer. Other animals and plants were buried upright, frozen in place, not flattened like typical fossils. If the scientists are right, this pegs the asteroid impact to a spring day in the Northern Hemisphere, which would have made its animals and plants more vulnerable than those in the Southern Hemisphere, where they could have already begun winter hibernation. More fascinating clues in our quest to understand the event that made way for mammals, like us, to inhabit the Earth.

    2 min

  8. 2D AGO

    Twister Myths

    Spring is tornado season, so let’s take a look at a few twister myths and how the truth about them can keep you safe. The first myth is that spring is tornado season! While it’s true more than half of those in the Northern Hemisphere do occur in April and May, they can occur in any month of the year. It’s also a myth that tornadoes never strike the same place twice. Some places have had three in one day. Others have had one on the same day in three consecutive years. It’s a myth that tornadoes won’t cross bodies of water or form in mountains or cities. While that’s less likely, they’ve hit several urban areas in the southern U.S. and jumped over the Mississippi River. It’s a myth that you can outdrive a tornado in your car. Tornadoes can travel 60 miles an hour or more and move unpredictably. Your car could be picked up by one of them. Parking under a bridge or overpass could actually be more dangerous because those structures can channel and intensify the wind and debris. If a tornado is coming toward your car, the safest thing to do is get out, move away and find shelter in a ditch, or lying face down in a flat field. Another myth is that air pressure will explode a house’s windows outward. It’s actually flying debris carried by the wind that’s the most dangerous part of a twister—and that’s what breaks windows. So don’t worry about opening them; that’s precious time you could use taking shelter. You can find more tips to stay safe during a tornado on EarthDate.

    2 min
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About

EarthDate is a short-format weekly audio program delivering concise, science-based stories about the Earth: its geology, environments, and the processes that shape our planet over deep time and today. Beginning in 2026, EarthDate is managed by Switch Energy Alliance and hosted by SEA's founder Dr. Scott W. Tinker. Together, we explore earth systems, natural resources, and their relevance to everyday life, with a focus on clear, accessible science education for broad audiences. EarthDate is written and directed by Emmy-winning filmmaker Harry Lynch, and researched by Lynn Kistler. We search for captivating stories to remind listeners that science can enlighten, educate and entertain.

Information

  • Creator
    Switch Energy Alliance
  • Years Active
    2K
  • Episodes
    300
  • Rating
    Clean
  • Copyright
    © Copyright 2026 EarthDate
  • Show Website
    EarthDate