Asteroids are artifacts of water's presence in the solar system

Asteroids are the rocky remains of the solar system's formation

These celestial bodies were not integrated into the precursors of planets about 4.6 billion years ago and instead continue to orbit the sun, primarily within a band between Mars and Jupiter—the asteroid belt.

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.

Ceres—the largest object in the asteroid belt—may have once harbored a muddy ocean

NASA's Dawn mission revealed Ceres' surface composition, which contains salts, water ice, and organic material. Ceres' ocean likely froze over entirely in the past, when the presence of water may have allowed life to exist.

Asteroids were discovered by 18th-century planet hunters

While looking for a planet between Mars and Jupiter to coincide with an apparent mathematical pattern in the distances of known planets from the sun, a group calling themselves the "Celestial Police" discovered multiple objects that fell into a new classification.

Critical organic molecules have been found on an asteroid

NASA's OSIRIS-REx mission returned samples containing amino acids and nucleobases from asteroid Bennu. Without Bennu having been destroyed—as is common for asteroids that enter Earth's atmosphere—its samples serve as a time capsule of the solar system's early chemistry.

Jupiter may have affected the trajectory of the asteroid that wiped out the dinosaurs

Despite its reputation as Earth’s cosmic shield, Jupiter’s gravity pulls more asteroids into Earth-crossing orbits. Simulations show that Earth experiences over three times more asteroid impacts because of Jupiter’s influence than if Jupiter didn’t exist.

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.

Why the existence of extremophiles greatly improves the odds of life beyond Earth

The conditions for life have long been thought to include liquid water, an energy source, and the essential elements for organic molecules within environments on or near Earth's surface. However, because extremophiles thrive in far more inhospitable environments, astronomers now analyze exoplanets whose characteristics indicate environments that fall within a broader range of possibilities when searching for signs of extraterrestrial life.

Comets serve as time capsules of the early solar system

The frozen objects preserve the molecular composition of the solar system's formation, dating back about 4.6 billion years. Spectral analysis of the gases they release when heated upon approaching the sun in eccentric orbits reveals this composition and helps assess solar system formation models.

Jupiter’s size forced the creation of modified planetary formation models

Since solar winds remove gases from protoplanetary disks within millions of years of a star’s birth, models needed to provide a mechanism to jump-start Jupiter’s formation and growth. The solution involved incorporating pebbles of matter into the disk.

Solar wind may have contributed to Mars losing its atmosphere

Scientists believe that over hundreds of millions of years, energetic particles from the sun colliding with atmospheric particles, flinging them away from Mars' weak gravitational field like colliding billiard balls. As atmospheric pressure decline, water also evaporated away from the surface.

Visualize water's abundance across the solar system, and its relative rarity on Earth

Despite covering almost three-quarters of its surface, water only makes up about 0.12% of Earth's volume. Water in some of Jupiter's and Saturn's moons comprises a larger share of those celestial bodies and of the total water in the solar system. For example, Jupiter's moon Ganymede is believed to harbor almost nine times Earth's oceans beneath its icy shell.

Ice found in another star system for the first time

NASA's James Webb Space Telescope has discovered frozen water in a young star system. The ice is similar to that found in Kuiper Belt objects in our solar system, and provides insights into planetary formation processes.

The Hubble Space Telescope made discoveries within our solar system and across the universe

The observatory helped confirm the presence of water on Jupiter's moon Europa, and uncovered seasonal variations on planets like Uranus. It also observed exoplanets and gravitational lensing, proved the existence of supermassive black holes at the centers of galaxies, and detected the accelerated expansion of the universe.

About 20% of asteroids are metal worlds similar to Earth's core

The biggest of these (that we know of) is 16 Psyche. Measuring 140 miles across, its iron and nickel content is potentially worth 10,000 quadrillion dollars. NASA’s mission to Psyche—reaching the asteroid in 2029—will study it to learn about its formation.

A chemical overview of water, whose uncommon properties help sustain life on Earth

The uneven distribution of charge in water molecules allows them to bond to each other and to surfaces, enabling them to move against gravity, including up plants through roots and stems. These bonds also keep water in a liquid state over a wider temperature range and make it less dense as it freezes. This causes ice to float and form an insulating layer for underwater ecosystems, from which all life originated.

Shooting stars, or meteors, are fragments of asteroids and comets that burn up as they enter Earth's atmosphere, creating streaks in the sky called meteor showers.

Explore the known asteroids, comets, and spacecraft involved in asteroid studies within our solar system with 'Eyes on Asteroids,' a 3D visualization from NASA.

Remnants of another planet that helped form the moon may be beneath Earth's surface

Large mantle structures beneath Africa and the Pacific Ocean may be the buried remains of Thea, a large Mars-sized planet that collided with Earth. The theory is supported by isotopic evidence from volcanic and lunar rocks.

More than 90% of the atoms in the human body were forged by stars

Excluding all of the universe's hydrogen and most of its helium and lithium that formed in the Big Bang, elements found in significant amounts in our bodies formed through nuclear fusion within stars, collisions between neutron stars, or stars undergoing supernova. For example, all of the oxygen (65% of our mass) came from massive stars exploding.

Shooting stars, or meteors, are fragments of asteroids and comets that burn up as they enter Earth's atmosphere, creating streaks in the sky called meteor showers.

The Viking landers were the first spacecraft to conduct experiments on Mars

NASA’s Viking 1 and 2 missions tested soils for signs of life, captured images, and studied the Martian atmosphere, revealing evidence of ancient water flow, volcanic soil, and a thin carbon dioxide atmosphere.

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.

Understanding why charged particles from the sun protect Earth from more dangerous particles

The solar wind engulfs the solar system in a protective bubble called the heliosphere, which was first theorized in the late 1950s based on studies of cosmic rays—high-energy particles traveling through space at near light speed. The heliosphere shields the solar system from much of this ionizing radiation originating elsewhere in the Milky Way.

One researcher posed a theory that aliens played a significant role in human evolution

Researcher Zecharia Sitchin proposed that Sumerian cuneiform tablets revealed that Sumerian gods were aliens who landed on Earth in Mesopotamia and influenced the creation of modern humans. While his ideas gained cultural interest, they are widely rejected by mainstream scholars.

Technologies developed for the ISS have brought benefits to people on Earth

About 93% of water used onboard the International Space Station is recycled through filtration and purification systems that have since been used in regions lacking access to clean water. Treatments to mitigate bone loss and muscle atrophy in astronauts can also help aging adults.

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.

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.

What are the Pillars of Creation?

The Pillars of Creation, recently photographed by the James Webb Space Telescope, are a gas-and-dust-filled space region 7,000 light years away where young stars are being born in the aftermath of a supernova. Learn why scientists say the formation has been long destroyed.

Before humans, the Soviet Union and the United States sent animals—including apes, dogs, and cats—to space during the Space Race.

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.

After NASA's Voyager 1 captured Earth as a single pixel as it left the solar system in 1990, astronomer Carl Sagan used the image to reflect on humanity's fragility and the responsibility to protect 'the only world we've ever known.'

Planeterrellas create artificial auroras that mimic the atmospheric displays of light by setting up an electric field between two metal balls in a jar filled with a small amount of air.

Most of the observable universe's volume consists of voids and supervoids—enormous regions of space with little to no galaxies, stars, or light.

All rainbows are 'raincircles' caused by water droplets separating white sunlight into a spectrum of colors, but Earth's surface blocks the bottom half of the circle from our line of sight.

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

Coral reefs get their colors from zooxanthellae—microorganisms that line corals' digestive tracts and provide them with sugars in exchange for a home within this protective tissue.

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.

Sunflowers have long been a symbol of nuclear disarmament because they can extract large amounts of radioactive cesium from soil.

The American cockroach is actually from Africa, an apparent hitchhiker aboard ships carrying enslaved people, with evidence suggesting the bug may have arrived in the New World as early as the 1600s.

The animatronic shark from Steven Spielberg's 'Jaws,' the first modern blockbuster, was a complex underwater apparatus called 'Bruce.'

SpaceX's S-1 or 'prospectus' revealed many previously unknown details about the company, including its unprofitability despite doing $18.7B in revenue in 2025, exactly how many voting shares Elon Musk will have in the company (roughly 85%), and more.

Stanford built a Google Maps for the Roman Empire, revealing how much it cost to travel in the ancient world

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

Bone marrow (soft tissue found inside certain bones) generates roughly 500 billion new blood cells each day

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.

One disco producer saw 'Star Wars' four times on its opening weekend and was so inspired that he recorded the album 'Star Wars and Other Intergalactic Funk,' which produced a chart-topping single.

The US dollar is the most widely circulated currency in the world, and is involved in nearly 90% of global transactions

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.

To reduce wrinkles in clothing, research recommends gentle wash cycles with more water and tumble drying with smaller loads and longer times.