Abiogenesis explains how Earth's natural processes could have formed organic matter

Evidence suggests the first cells on Earth were bacteria

About 4 billion years ago, these single-celled organisms harvested carbon dioxide and sunlight to produce their own food and oxygen, setting the stage for the evolution of oxygen-breathing life forms. Archaeabacteria, which thrive on inorganic molecules in extreme habitats on Earth today, were also among the earliest organisms.

Hypotheses on the origins of Earth's water, from comets and asteroids to magma oceans

Before Earth's atmosphere formed, any liquid water would have boiled off, preventing the accumulation of water early on to create today's oceans. Planetary scientists continue to debate whether this water was delivered later from comet or asteroid collisions or via reactions between iron oxide in Earth's molten surface and hydrogen gas from the planetary nebula.

Early Earth lifeforms likely made energy via mineral reactions, not sunlight

Earth's initial atmosphere was filled with carbon dioxide, methane, and water, with most oxygen locked away in the rocky crust. Over time, bacteria evolved to slowly release that oxygen into the atmosphere by breaking down rock.

Demystifying the claim that crude oil is inorganically created and a renewable resource

The abiogenic petroleum theory holds that fossil fuels originate in Earth's mantle and are constantly replenished, rather than formed by microorganisms over millions of years. While inorganic chemical processes can produce simple hydrocarbons, the range of complex molecules found in crude oil suggests an origin from a diverse set of organisms. Isotope analyses of these molecules also support the model that they originated from living things that preferentially take up certain isotopes over others.

Panspermia, the theory that cellular life came from a different planet

One of the most profound mysteries of human life on earth is the presence of living cells: organic, self-organizing, reproducing creatures with a drive to survive within given set conditions. Traditional theories posit life came from divine...

The key ingredients to life on Earth—and elsewhere

Life can only arise in incredibly specific conditions, an abundance of certain substances like water and phosphorus, lots of time, and the right proximity to a heat-and-light-providing star. These two experts on evolution of life say above all, life requires luck. Here's a list of eight ingredients to life.

RNA may have allowed life to exist before DNA

The emergence of living organisms from non-living matter—abiogenesis—requires both a molecule that encodes genetic information and proteins that perform biochemical processes. However, because DNA and protein depend on one another, some biologists theorize that RNA, which can both store information and perform functions, preceded both and originated life.

Genetic analysis indicates that every organism on Earth evolved from a single cell

LUCA—the last universal common ancestor—lived about 4.2 billion years ago and likely obtained energy through the conversion of carbon dioxide and hydrogen gas consumed from atmospheric gases at the ocean's surface or hydrothermal vents—openings on the seafloor where fluid warmed and enriched with minerals by Earth's interior is expelled.

Spontaneous metabolism may give clues to origins of life

Read this article to learn more about the discovery that suggests that metabolism could have begun spontaneously on our planet—and why it means that scientists may need to rethink how we define life’s origins. A team of researchers at the...

Humans have existed for just 0.004% of Earth’s history

Born from the remains of the molecular cloud that birthed the sun, Earth experienced planetary-scale collisions, asteroid impacts, and lava seas. Life became possible after the planet cooled and formed a thin crust, atmosphere, and oceans.

How Oceans were formed

Nonprofit organization American Oceans briefly explains the formation of the oceans, which cover over two thirds of Earth’s surface. They were formed by centuries of rain from the condensation of Earth's original gasses.

A four-billion-year-old meteorite reignited the debate about life on Mars

Recovered from Antarctica in 1984, ALH84001 contained organic compounds, magnetite and iron sulfide grains of potential biological origin, and features that resembled fossilized bacteria. With technological advancements, scientists found abiotic origins for these features in the following decades.

Europa's deep ocean may hold the conditions needed to support alien life

Beneath its frozen crust, Europa hides a salty ocean heated by tidal forces from Jupiter. This environment may resemble Earth's deep-sea hydrothermal vents and have allowed for the development of life over billions of years.

Learn about historical uses of bioremediation, the oldest cleanup method on Earth

Biochemical reactions that decompose complex molecules into simpler ones have occurred on Earth for as long as life has existed and have gradually transformed the planet into a celestial body that is increasingly habitable to greater biodiversity. Along the way, modern, human-made bioremediation techniques began to take shape in Santa Maria, California, in the 1960s.

The cycling of carbon via tectonic activity may have facilitated life on Earth

Plates sinking into Earth’s mantle pull carbon from the surface, helping stabilize the atmosphere and climate by removing greenhouse gases from volcanic eruptions. At the same time, magma is a significant contributor of heavy metals and other crucial minerals for life to the surface.

Lining up every microbe on Earth would stretch to about 105,000 light-years

There are about 10²⁷ such organisms on the planet, many of which are adapted to produce energy through uncommon reactions in unconventional environments, such as within rocks or near volcanoes on the ocean floor. Studies of these organisms have reframed astrobiologists' search for life beyond Earth by broadening the parameters under which life can exist.

Geode formation begins with trapped gas bubbles in igneous or sedimentary rock

Over thousands or millions of years, water seeps into the cavity created by the bubble and deposits minerals, which slowly build and crystallize into quartz, agate, amethyst or other crystals.

Fossils form in environments where dead organisms can be rapidly buried

Such landscapes enable corpses to be encased by terrain before significant decay occurs. They are most commonly found in river deltas and sinking coastal regions, where sediments accumulate over time until geological forces expose the areas to erosion, revealing embedded fossils.

An interactive look at Earth's history

This interactive module allows students to explore the science of Earth’s deep history, from its formation 4.5 billion years ago to modern times.

Breaking down the challenges of alkaline environments and how extremophiles survive them

These areas are far less acidic than the interiors of most organisms' cells, and this imbalance draws protons that are needed for various metabolic processes, including energy production, out of cells. To counter these effects, some alkaliphiles have developed stronger proton regulation across their cellular membranes and proteins that drive these processes with greater stability amid such acidity imbalances.

The theory of axiogenesis may explain the matter-antimatter asymmetry in our universe

Axiogenesis suggests that a theoretical particle field that evolved after the Big Bang may have spun like a marble around a wobbly “Mexican hat” energy landscape, producing excess matter over antimatter. This theoretical particle—the axion—may also make up dark matter, solving an additional mystery in astronomy.

Why 75% of ocean animals glow

About 75% of ocean creatures can make their own light. It's called bioluminescence—and it all comes down to a special chemical reaction happening inside their bodies.

How solar systems form

Learn how our sun, the planets, and other solar system bodies came to be with these videos and an infographic from NASA. Use this resource to visualize how the solar system formed and to model and describe the process.

David Attenborough discusses creationism and his position as an agnostic

Attenborough argues that accounts of humanity's origins from different cultures cannot all be correct because they often differ, whereas geological records are consistent worldwide, meaning science provides the best understanding of the natural world. However, he acknowledges that, just as insects lack awareness of human goings-on, humans may be unaware of the existence of a deity.

Create anything from the elements in Little Alchemy 2

Various ancient cultures believed the most abundant substances in the world were its basic elements: earth, water, air, and fire. We may know better now, but you can make almost anything from those four things. Little Alchemy 2 is a fun, cartoonish game that allows users to create more complex items from simple substances.

Scientists can determine Earth's past climate conditions by analyzing air trapped in microscopic bubbles within ice cores—columns of compressed snow layers that build up over hundreds of thousands of years.

Massive blooms of microscopic plankton called dinoflagellates produce the neon blue light seen in glowing tides.

Artificial coral reefs have been 3D printed from nontoxic, biodegradable terracotta clay, which coral polyps have used as a foundation for rebuilding marine ecosystems.

An investigation suggests a Scottish island became awash in forever chemicals via seafoam and seaspray—raising questions about what that means for the safety of other coastal areas.

The first line of 'immortal' human cells, which can divide indefinitely and are used in scientific research, was nonconsensually taken from a Black woman.

Apollo astronauts left items in the moon's 'toss zone,' including golf balls, family photos, and bags of human waste, to make room for lunar rocks.

The boiling temperature of water decreases with increasing elevation because the molecules need less energy to overcome the lower atmospheric pressure associated with thinner air.

See how each of the more than two million known species relates to each other—and to common ancestors—in this zoomable tree of life.

How fusion—which releases energy when two lighter atoms combine to form a heavier atom—differs from fission

Scientists have struggled to pin down Ebola's natural reservoir species for decades, but the available evidence suggests that it's very likely fruit and insect-eating bats found in Africa.

Learn more about the history of fireworks, which dates back to an accidental invention during an alchemist's quest for information about immortality.

Pure water does not conduct electricity because this flow of energy requires the movement of charged particles, and water is a neutral molecule.

Chaos theory—informally known as the butterfly effect—is the reason why weather forecasts are presented with probabilities rather than certainties.

Children are now three times more likely to say they want to be a YouTuber when they grow up than an astronaut, with some even attending 'YouTube camps' that teach kids how to create content for the platform.

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

According to the physics of black holes, our 4D reality may be a hologram—a projection of information coded on a 2D surface on the edge of the universe.

English mathematician Ada Lovelace wrote the first computer algorithm a century before computers existed and hypothesized that computing devices would one day be able to compose music—foreseeing the generative AI systems of today.

While the sun's gravity keeps the planets in orbit, their gravity also pulls on the sun, causing it and everything else in the solar system to orbit around a mutual balance point called the barycenter—the true center of the solar system.

Urushiol, the oily toxin in poison ivy, can remain allergenic on clothing for years.

The Dracula character, now seen as the vampire archetype, was inspired by a seafood-induced nightmare its creator experienced.

Studies suggest when you sleep is as important as how much you get, and syncing with your circadian rhythms may lead to less fatigue and improved long-term health outcomes

The name 'Silicon Valley' arose from the founding of Shockley Semiconductor Laboratory in Fairchild Semiconductor in 1956-57, founded near Stanford University in Palo Alto

Jimmy Carter signed a 1978 bill that legalized home brewing, a move credited with kick-starting the craft beer industry.

An initial public offering or 'IPO' is the process of a private company becoming public by putting shares of the company on the stock market for purchase.

SpongeBob exemplifies Aristotle's philosophy for living well because he understands that happiness doesn't come from external factors like money, recognition, or power.