Discover how Earth works, from the rocks beneath our feet to the forces that shape its surface. Explore geology, minerals, plate tectonics, earthquakes, volcanoes, and Earth’s long history. This category explains the processes behind our planet’s landscapes and the changes that continue to shape them.
Earth Science How do scientists determine the age of rocks and fossils?
IntroductionScientists determine the age of rocks and fossils using a combination of physical observations and laborator...
Earth Science Why is Earth’s core still so hot after billions of years?
IntroductionThe Earth's core remains extremely hot even after roughly 4.5 billion years. That heat comes from several lo...
Earth Science Why do some rocks split into perfect flat sheets?
IntroductionSome rocks split into remarkably flat, even sheets that look as if they were cut by a blade. This behavior a...
Earth Science What makes some types of ground shake more strongly during earthquakes?
IntroductionDuring earthquakes some places shake violently while nearby areas feel only minor trembling. The difference ...
Earth Science What causes the ground beneath us to slowly rise or sink?
IntroductionThe ground beneath us can slowly rise or sink over years, decades, or centuries. These gradual changes—calle...
Earth Science How does a rock turn into another kind of rock?
IntroductionRocks are not fixed, lifeless objects — they change. Through heat, pressure, melting, weathering and chemica...
Earth Science What are mid-ocean ridges, and why do they matter so much?
IntroductionMid-ocean ridges are underwater mountain chains where Earth's tectonic plates pull apart and new oceanic cru...
Earth Science Why are aftershocks sometimes almost as strong as the main earthquake?
IntroductionAfter a large earthquake, it is common to feel more shaking — sometimes so strong it seems nearly as powerfu...
Earth Science How are new oceans born?
IntroductionOceans are vast, dynamic features of Earth that shape climate, biodiversity, and the planet's surface. But o...
Earth Science Why does Earth have a magnetic field in the first place?
IntroductionEarth has a magnetic field that surrounds the planet and guides compasses, protects the atmosphere, and crea...
Earth Science Why can the same earthquake feel so different in nearby places?
IntroductionEarthquakes often feel very different from one neighborhood to the next. The same seismic event can be barel...
Earth Science How do volcanic islands rise from the middle of the ocean?
IntroductionVolcanic islands can appear to sprout from the middle of the ocean as if by magic. In reality, their formati...
Earth Science Why are some rocks billions of years old while others formed yesterday?
IntroductionRocks on Earth range from billions of years old to brand-new fragments formed yesterday. The difference depe...
Earth Science Why are there so many volcanoes around the Pacific Ocean?
IntroductionThe Pacific Ocean is ringed by hundreds of volcanoes, from deep-sea vents to towering island peaks. This hig...
Earth Science How can fossils reveal the environment where an ancient animal lived?
IntroductionFossils are more than old bones or impressions in rock. They are clues left behind that help scientists reco...
Earth Science How do scientists know what lies deep inside Earth?
IntroductionWe cannot dig to Earth’s center, so scientists use indirect clues to learn what lies beneath our feet. By co...
Earth Science What gives rocks their different colors?
IntroductionRocks come in a dazzling range of colors — from the deep black of basalt to the green of olivine-rich perido...
Earth Science Why can a volcano stay quiet for thousands of years and then erupt?
IntroductionVolcanoes can appear to sleep for centuries or millennia and then suddenly erupt. This happens because the p...
Earth Science Why do some fossils preserve soft tissues while most do not?
IntroductionFossils are usually mineralized bones, shells, or imprints. Occasionally, however, fossils preserve soft tis...
Earth Science What happens when two continents collide?
IntroductionWhen two continents collide, the Earth's surface reshapes in dramatic ways over millions of years. This coll...
Earth Science How do scientists locate the exact source of an earthquake?
IntroductionWhen an earthquake shakes the ground, scientists can determine not only when it happened but also the exact ...
Earth Science Why are some mountains still growing while others are shrinking?
IntroductionSome mountains are still getting taller while others are slowly shrinking. The difference comes down to the ...
Earth Science How can rocks reveal what Earth looked like millions of years ago?
IntroductionRocks act as pages in Earth's long history book. By studying where rocks formed, what they contain, and how ...
Earth Science Why are the deepest parts of the ocean found near plate boundaries?
IntroductionThe deepest parts of the ocean are not scattered randomly. They are closely linked to the edges of Earth's t...
Earth Science What makes crystals grow inside rocks?
IntroductionMany people have seen shiny crystals embedded in ordinary rock and wondered: how did those perfect geometric...
Earth Science What would happen if Earth’s magnetic field disappeared?
IntroductionEarth’s magnetic field is an invisible shield generated by motions in the planet’s molten core. It guides co...
Earth Science Why do continents move, and how fast are they really going?
Continents move because they are part of enormous tectonic plates that slowly shift across Earth's surface. These plates...
Earth Science How does pressure deep underground transform ordinary rocks?
IntroductionDeep beneath Earth’s surface, ordinary rocks are transformed by forces very different from the weather and w...
Earth Science How do underwater mountains form without ever reaching the surface?
IntroductionUnderwater mountains — often called seamounts — rise from the ocean floor but never break the surface. They ...
Earth Science Why is the Atlantic Ocean still getting wider?
IntroductionThe Atlantic Ocean is slowly getting wider: a fact grounded in plate tectonics, the science that explains ho...
Earth Science Why are some rocks surprisingly light or unusually heavy?
IntroductionRocks are usually thought of as heavy, solid things, but some are surprisingly light while others are unusua...
Earth Science How can rocks bend without breaking?
IntroductionRocks are often thought of as hard, unchanging materials. Yet under the right conditions they can deform, fl...
Earth Science Can tiny earthquakes tell us anything about larger ones?
IntroductionSmall earthquakes, often called microseisms or microearthquakes, are common across fault zones. Scientists s...
Earth Science How are fossils preserved inside solid rock?
IntroductionFossils are the preserved remains, traces, or impressions of once-living organisms. Many fossils are found l...
Earth Science How can an earthquake permanently change the shape of the land?
IntroductionEarthquakes can suddenly shake the ground, but they can also produce lasting changes to the landscape. This ...
Earth Science Why do volcanoes form in some places but not others?
IntroductionVolcanoes are dramatic reminders that Earth’s interior is active. But they don’t appear randomly: some regio...
Earth Science How can a missing rock layer represent millions of years?
IntroductionIn geology, a missing rock layer — often called an unconformity or gap in the stratigraphic record — can rep...
Earth Science Why do some rocks contain holes and bubbles?
IntroductionRocks with holes, pockets, or visible bubbles catch the eye: pumice that floats, basalt pocked with rounded ...
Earth Science Why are layers of rock such powerful records of Earth’s past?
IntroductionLayers of rock—often visible in cliffs, road cuts, riverbanks, and quarries—are natural archives that preser...
Earth Science How can you tell how a rock formed just by looking at it?
IntroductionRocks record Earth’s history. By looking at texture, composition, layering, and other visible features you c...