The Earth Isn’t a Perfect Sphere

If you had to make a model of the solar system in an elementary science class, your nine planets (or eight, depending on your age) were likely perfect foam spheres. While that’s a pretty good approximation, it’s not entirely accurate. The Earth is actually an irregularly shaped ellipsoid — its middle bulges due to the centrifugal force of its constant rotation. Scientists have determined that the Earth’s sea level is actually about 13 miles farther from its center at the equator than at the poles.

The Earth’s Surface Is “Recycled” Every 500 Million Years

Approximately every 27 days, humans replace their skin. The Earth undergoes a similar process — it just takes 500 million years. As tectonic plates ram into each other, creating what are called subduction zones, the plates dip below lighter continental plates. The subducted rock is heated into magma and becomes future lava plumes forming new land masses. Scientists used to believe that this process took nearly 2 billion years to complete, but new analysis of basaltic lava on Mauna Loa volcano in Hawaii proves that Earth recycles its “skin” in about a quarter of that time, or every 500 million years.

The Remnants of an Ancient Planet Might Be Buried Inside the Earth

The Earth’s birth some 4.6 billion years ago was a pretty raucous one. Scientists refer to Earth’s first 600 million years as the “Hadean Eon,” a reference to the fact that the planet was little more than a quagmire of molten rock at the time. During this stretch of years, the Earth was also constantly bombarded by planetesimals (small bodies of rock or ice) that existed in the sun’s protoplanetary disk — a dense field of gas, dust, and rock that orbits newly formed stars. One of the biggest of these celestial bodies was a Mars-sized protoplanet named Theia, which scientists theorize smashed into Earth only 30 million to 100 million years after the solar system’s formation. The resulting collision was so cataclysmic that the debris ejected into space formed Earth’s moon (possibly in a matter of hours). In 2021, a geologic survey uncovered mysterious rocks at the base of the planet’s mantle, suggesting that remnants of this ancient run-in might still be found within the Earth itself.

Parts of Antarctica Might Not Have Seen Rain for 14 Million Years

Antarctica is best known as the barren southernmost continent, home to glistening glaciers and snow-packed peaks that never seem to melt. Despite being surrounded by an endless supply of frozen water, the coldest continent on Earth is also one of the driest — so dry, in fact, it’s technically considered a desert.

True deserts typically receive less than 9.8 inches of rainfall per year. Antarctica, which averages just 2 inches of annual precipitation, meets this definition; at 5.5 million square miles, it reigns as the world’s largest and coldest desert. And Antarctica’s harsh climate doesn’t equally share its annual allotment of rain; some areas are practically devoid of showers. The McMurdo Dry Valleys, a snow-free region located west of the McMurdo Sound, are considered one of the driest places on Earth. Some researchers believe the flat-topped hills haven’t seen measurable precipitation or flowing water in 14 million years — an extreme drought that’s unlikely to end any time soon thanks to the placement of nearby mountains, freezing temperatures, and unforgivingly strong winds that can reach up to 200 miles per hour.

The Highest Point From the Earth’s Center Isn’t Everest

What is the world’s tallest mountain? The answer is actually deviously complicated. Most people likely think it’s Mount Everest, and in a way, they’re not wrong. At 29,032 feet tall, the Himalayan giant is the highest point above global mean sea level. But then there’s Hawaii’s Mauna Kea, a mountain that stands some ​​33,500 feet but with more than half of its rocky stature hidden below the surface of the Pacific. And there is a third contender — a mountain that few people could even point out on a map. Ecuador’s Mount Chimborazo is only the 39th tallest peak in the Andes, but it has a secret geographic advantage in the form of Earth’s equatorial bulge. The Earth isn’t a perfect sphere (see above) and because of its natural centrifugal bulge around its waistline, this relatively inconspicuous mountain is actually the highest terrestrial point from the center of the Earth — a full 2,072 meters (nearly 6,800 feet) higher than its Himalayan competition.

Earth Is the Only Known Planet That Supports Life

Maybe the most amazing fact about Earth is that it’s the only planet we know that supports life at all. A lot of things had to go right for this to be possible. For one, our planet is perfectly distanced from the sun in what scientists call “the Goldilocks zone,” because it’s not too hot but also not too cold (most life has a tough time living in temperature extremes). The Earth is also protected from solar radiation thanks to its magnetic field, and kept warm by an insulating blanket we call the atmosphere. And most importantly, it has the right building blocks for life — mainly water and carbon.

While the existence of life is Earth’s most distinguishing feature among all the known planets, moons, and exoplanets, it might not always be an outlier. Scientists have classified some exoplanets as “superhabitable,” meaning they have conditions greater than Earth’s for supporting life. Even places like Enceladus, a moon of Saturn, or Europa, a moon of Jupiter, could possibly be hiding life somewhere on their surface or oceans.

The Majority of Earth’s Human Population Lives in One Hemisphere

Although the Earth’s hemispheres are equal in geographic size, the Earth’s population is not divided similarly. Roughly 90% of Earth’s human population lives in the Northern Hemisphere, which also accounts for most of the planet’s landmass. The Northern Hemisphere is made up of 39.3% land (the rest is ocean) and also contains many of the world’s most-populated cities, while the Southern Hemisphere only is 19.1% land.

Over Half of the World’s Population Lives on a Single Continent

Earth’s continents are similarly unequal in population distribution — it’s estimated that 60% of Earth’s population (4.7 billion people) lives in Asia. Made up of 48 countries, Asia is also home to the two most populous nations in the world, China and India. China is estimated to currently have 1.4 billion people living in the country, while India has around the same. Together, the two countries account for over half of Asia’s total population.

Japan Is Home to the World’s Most Populated City

China and India may be the nations with the highest population, but Japan is home to the most populated city in the world. As of 2023, the population of the Tokyo metropolitan area was estimated to be an astounding 35.8 million people, with 40% of the population living in the city center. Greater Tokyo’s population is almost equivalent to the total sum of the 25 most populated cities in the U.S., which adds up to 37.8 million people. It’s also 1.5 times larger than the next most populous metro area, Seoul.

There’s a Town in Nebraska With a Population of 1

In the lonesome grasslands of Nebraska near the South Dakota border lies the municipality of Monowi. The town’s sole resident is Elsie Eiler, a woman in her 80s who is the town’s mayor, clerk, librarian, and treasurer. As Monowi is an incorporated town for the purposes of the U.S. Census, Eiler receives state funding for municipal road work. However, she has to raise her own funds for the town’s taxes to pay for the street lighting and water.

The Entire World Population Could Fit Inside Los Angeles

The world population grows larger every year, but we aren’t exactly running out of physical space. In fact, all 7.8 billion of us could easily fit inside Los Angeles. Research has shown that you can fit about 10 people into a square meter, crowded-elevator style; Los Angeles is about 1.2 billion square meters, which means that if we all squeezed together, the city could theoretically fit around 12 billion people. However, we couldn’t do much more than pose for a quick photo before going our separate ways, as there isn’t enough space in L.A. for everyone to actually live in such close quarters.

In the Diomede Islands, You Can Cross From One Day Into Another

Seeing into the future is supposed to be impossible. But if you travel to the Diomede Islands of the Bering Strait, the impossible becomes reality. The Diomedes consist of two remote islands, Big Diomede (part of Russia) and Little Diomede (part of Alaska). They’re only 2.4 miles apart, but the international date line runs in between them. That means that when you’re in the Alaskan fishing village of Little Diomede and looking at your Russian neighbor, you’re actually gazing into tomorrow. It’s no wonder these landmasses have been nicknamed the Yesterday and Tomorrow islands.

Coast Redwood Trees Are the Tallest Beings in the World

With a narrow range stretching for about 450 miles, from Big Sur to southern Oregon, coast redwoods (Sequoia sempervirens) are the tallest living beings in the world — and one in particular surpasses them all. Named after a titan in Greek mythology and found in California’s Redwood National Park, Hyperion stands 380 feet tall. That’s 65 feet taller than London’s Big Ben and 10 feet taller than the previous record holder, another coast redwood.

A redwood’s size is only one of its many fascinating features. Their root systems are relatively shallow (only 6 to 12 feet deep), but can grow more than 100 feet outward from the trunk, giving them stability against heavy winds and flooding. They’re also old — really old — with some redwoods alive today estimated at more than 2,000 years old. That means they were around during the Roman Republic (“sempervirens” means “always flourishing,” after all). In fact, their age may be one reason these trees can grow so tall.

The Earth’s Shape Is Constantly Changing

Many things affect the shape of the Earth. The drifting of tectonic plates form entirely new landmasses, and the Earth’s crust is still rebounding from the last ice age 16,000 years ago. While these minute adjustments go mostly unseen, other shape-altering events — such as earthquakes, volcanic eruptions, and asteroid strikes (RIP to our Cretaceous friends) — are hard to miss. But the Earth also changes shape by the hour, and humans can watch it happen … sort of. Every day (roughly), the Earth experiences two periods of high and low tide, where the gravitational effects of the moon and sun affect the movement of our oceans, and as a result, the shape of the planet, if only temporarily. So even if the Earth’s shape isn’t exactly perfect, it’s certainly dynamic.

About 80% of the Earth’s Oxygen Comes From Plankton

Prochlorococcus, a species of ocean-dwelling phytoplankton, only measures about 0.6 micrometers. It’s the world’s smallest organism capable of photosynthesis — so small that 20,000 or so can reside in a single water droplet. But its impacts are so huge that an estimated one out of every five breaths you take is thanks to this miniscule microbe. Prochlorococcus, along with many other types of plankton (organisms carried along by the tides and currents), create as much as 80% of the world’s oxygen. They also play a big role in sequestering carbon from the atmosphere, capturing about 40% of all the CO2 produced. That’s equivalent to the amount that would be captured by roughly four Amazon rainforests.

1% of the Earth’s Mass Contains All Known Life in the Universe

To call our planet one grain of sand on the beach that is the universe would be to vastly overstate its size. Yet however infinitesimal it is in the unfathomably grand scheme of things, Earth is home to all known life in the universe — and all of that life has been found in just 1% of the planet’s mass. That tiny fraction refers to Earth’s crust, which is 25 miles deep and has been home to every life-form ever known.

The Earth Shakes Every 26 Seconds, and Scientists Aren’t Sure Why

Like a lot of strange happenings, it was first noticed in the 1960s: a small seismic pulse, large enough to register on seismological instruments but small enough to go otherwise unnoticed, and occurring every 26 seconds. Jack Oliver, a researcher at the Lamont-Doherty Geological Observatory, first documented the “microseism” and sussed out that it was emanating from somewhere “in the southern or equatorial Atlantic Ocean.” Not until 2005 was it determined that the pulse’s true origin was in the Gulf of Guinea, just off Africa’s western coast, but to this day scientists still don’t know something just as important: why it’s happening in the first place. There are theories, of course, ranging from volcanic activity to waves, but still no consensus.

There Were Ginkgo Trees on Earth Before the Dinosaurs

There is no tree on Earth like the Ginkgo biloba. It’s the sole survivor of its genus, family (Ginkoaceae), order (Ginkgoales), class (Ginkgoopsida), and even its phylum (Ginkgophyta). In other words, it has no living relatives. Ancestors of the ginkgos now filling our parks and city streets lived on Earth 270 million years ago; for those keeping track, that means the ginkgo predates the Triassic Period (aka the beginning of the dinosaurs) by a cool 18 million years. The gingko is the oldest living tree species in the world — it’s been nicknamed a “living fossil.”

About 75% of the Earth’s Volcanoes Are Located on the Pacific Ocean’s “Ring of Fire”

About 1,350 potentially active volcanoes dot the Earth today, and the lion’s share of them can be found along a 25,000-mile-long horseshoe-shaped ribbon that borders the Pacific Ocean. This Circum-Pacific Belt, more commonly known as the “Ring of Fire,” is home to some of the most volcanically active areas in the world, including Southeast Asia, New Zealand, Japan, Chile, Alaska, and parts of the contiguous United States. These volcanoes are largely formed at subduction zones, when denser tectonic plates slip underneath lighter plates. This subduction turns the Earth’s dense mantle into magma, which eventually bubbles up as volcanoes.

The “Ring of Fire” is also home to about 90% of all earthquakes, and in the past 150 years, deadly volcanic explosions — from Indonesia’s Krakatoa in 1883 to Mount St. Helens nearly a century later — have happened along this dangerous stretch. But although the “Ring of Fire” is known for its destructive nature, it’s also a force of creation. Alaska’s Aleutian Islands are the result of Ring of Fire subduction zones, and many continental mountain ranges, such as the Cascades in the Pacific Northwest and the Andes in South America, also owe their existence to the subterranean drama unfurling just beneath the surface.

There Are More Trees on Earth Than Stars in the Milky Way

Astronomer Carl Sagan wrote in his 1980 book Cosmos that there were more stars in the universe than grains of sand on beaches on Earth — a statement that’s both wondrous and impossible to prove. But some scientists pondering similar ideas believe that there may be more trees on Earth than stars in the Milky Way galaxy. The theory stems from a 2015 study that attempted to determine how many living trees could be found on the planet, by estimating the number of trees living in different environments. Tropical and subtropical forests appear to have 43% of the world’s tree population, nearly double that of frosty boreal forests found in places such as Canada, Russia, and Norway. Other regions, including the temperate biome (central Europe and the U.S. Northeast), generally have the fewest number of trees. The combined estimates per zone lead some scientists to believe that Earth is home to roughly 3 trillion trees. Compared to NASA’s estimate of more than 100 billion stars in the Milky Way, it appears that trees far outnumber the Milky Way’s sparkling orbs.

There’s a Jellyfish That’s Considered Biologically Immortal

Immortality is the dream of ancient mystics and futuristic transhumanists alike, but for humans and most other animals on Earth, the promise of such longevity remains out of reach — that is, unless you’re a jellyfish known scientifically as Turritopsis dohrnii, and nicknamed the “immortal jellyfish.” The life cycle of most jellyfish begins with a fertilized egg that grows to a larval stage called a planula. Eventually, the planula attaches itself to a surface, and forms into a tubelike structure known as a polyp. These polyps eventually bud and break away into an ephyra, aka a young jellyfish, and these floating youngsters then develop into adult medusae capable of sexual reproduction.

Most species of jellyfish call it quits at this point, and eventually die like every other species on Earth — but not Turritopsis dohrnii. Instead, when this creature becomes damaged for whatever reason, it can revert to a blob of living tissue that eventually develops back into a polyp, and once again its developmental process repeats. Of course, this jellyfish isn’t immune to the numerous dangers of the ocean — whether from predators or climate change — but if left to their own devices, these incredible creatures can just go on living forever.

Modern Humans Have Been on Earth Less Than 0.01% of the Planet’s Existence

The Earth has been around for a while — about one-third as long as the universe itself. By comparison, Homo sapiens are the new kids on the block. Earth’s story began at the outset of the Hadean eon, about 4.6 billion years ago. It took 600 million years just for the Earth’s crust to take shape, another 300 million years for the first signs of microbial life to pop up, and about 3.2 billion years after that for life to really get going thanks to the evolutionary burst known as the Cambrian explosion. Several mass extinction events and some 465 million years later, mammals finally took center stage, but modern humans didn’t enter the biological limelight for another 65 million years. With the first Homo sapiens appearing around 300,000 years ago, humans have only been on planet Earth for 0.0067% of its existence.

Earth Is the Only Place in the Solar System Where Fire Occurs

Fire seems intrinsically linked to life on Earth. The fires of the Earth’s molten core formed the land we live on, forests are at their healthiest when they burn in a controlled manner to make way for new life, and even the legendary R&B group Earth, Wind & Fire paid homage to the stuff. In fact, Earth is the only place we know of where fire occurs. That’s because fire requires three things to exist: heat, oxygen, and combustible material. This “fire triangle” is only possible on Earth, as far as we know, because of the planet’s high levels of free oxygen. Travel to other planets and moons in the solar system, and there isn’t enough (or any) oxygen for fire to exist. As for the sun, which some people imagine as a giant ball of fire, it’s actually a giant collection of gas that glows thanks to the complex nuclear fusion occurring in its core.

There’s a Beach in the Maldives That Glows in the Dark

If you were wowed by those glow-in-the-dark stars on your bedroom ceiling as a kid, you may need to book a trip to the Maldives. The small nation of more than 1,000 islands in the Indian Ocean is home to at least one beach, on Mudhdhoo Island, that often glows in the dark — and it’s a completely natural phenomenon. We have ostracod crustaceans (aka seed shrimp) to thank for the effect, as the millimeter-long creatures have the ability to emit a blue light for as long as a minute or more. Though scientists are unsure why they do so, some believe it happens when a mass mortality event occurs.

That gorgeous seed shrimp glow is an example of bioluminescence — light produced by a chemical reaction within a living being. Seed shrimp are far from the only creatures who shine this way: The chemical reactions that create bioluminescence occur in other organisms whose bodies contain luciferin (light-emitting organic compounds; the name comes from the Latin “lucifer,” meaning “light-bearing”). That list also includes fellow ocean-dwellers such as firefly squid and sea sparkles, as well as fireflies, glow-worms, and certain bacteria and fungi on land. Some animals do it to lure their next meal, others as a kind of mating ritual, and still others use it to frighten, distract, or hide from predators. Good thing sharks and bats don’t find the sight as wonderful as we do.

Niger Has the Highest Birth Rate and the Youngest Population

The West African country of Niger has the highest birth rate in the world: Between 2015 and 2020, the average woman in Niger gave birth seven times. Unsurprisingly, this means that Niger has a very young population, with a median age of 15. In fact, with an estimated population of 22.93 million, roughly half of the people who live in Niger are under the age of 14.