Critical organic molecules have been found on an asteroid

In 2022, NASA's OSIRIS-REx spacecraft touched down on an asteroid

Dust of asteroid Bennu, slightly wider than the Empire State Building is tall, was found to be rich in carbon, nitrogen, and organic compounds essential for life. The presence of magnesium-sodium phosphate indicated Bennu may have broken off from a primitive ocean world.

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.

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

Asteroids contributed to planet formation and carried water from the solar system's outer reaches toward the center. They were also early providers of the necessary elements and conditions for life to evolve on Earth.

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.

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.

Questioning the results of life on K2-18b

An analysis of the atmosphere of an exoplanet called K2-18b identified the presence of biosignatures—molecules that are created by living things on Earth. This discovery may indicate life exists beyond Earth, but the lack of environmental data complicates the interpretation of results.

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.

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.

Biosignatures are the chemical fingerprints astrobiologists search for to find life

The 21st century has introduced advances making telescopes, cameras, and computers powerful enough to detect the presence of molecules associated with biological processes in distant atmospheres, expanding the search for life to include unreachable worlds.

Studies show the asteroid that killed the dinosaurs was from the outer asteroid belt

Isotopic evidence confirms the rock was a carbon-rich asteroid, likely born beyond Jupiter and later knocked into Earth's path after billions of years of orbital drift and gravitational nudges. Its path spanned over 4 billion years and ended in the extinction of 75% of life, including all nonavian dinosaurs.

Scientists determine the smells of objects in outer space

Using spectrographic techniques, scientists determine the chemical composition of planetary atmospheres, comets, and other objects in space. Combining these chemicals in labs on Earth has revealed locations in space that smell like nail polish remover, rotten fish, and urine.

Experiments suggest nuking a metal-rich asteroid may strengthen it

Scientists exposed meteorite samples to proton irradiation at CERN to mimic the effects of a nuclear detonation. The material exhibited greater resistance to breaking after the exposure, suggesting nuclear weapons may better serve to deflect asteroids, not break them.

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.

NASA monitors potentially hazardous asteroids and comets

Established in 2016, the Planetary Defense Coordination Office characterizes and tracks asteroids and comets passing within 30 million miles of Earth. Over 40,000 near-Earth asteroids have been discovered, although estimates suggest that about 14,000 more such objects remain to be found.

Exoplanet atmospheric gas patterns may indirectly provide evidence for life

When searching for life beyond the solar system, scientists first determine the range of distances from a star that liquid water—believed to be essential for life—can be found. Within this habitable zone, the presence of specific molecules in an exoplanet's atmosphere—detectable through spectral analysis—can indicate the presence of living things known to produce those compounds.

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.

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

Asteroids are often unobserved until they are days away from Earth

Even those large enough to cause local or regional damage are too small, dim, and far away to be observed readily from cosmological distances. New tools, like NASA's NEO Surveyor telescope, aim to address gaps in detection systems.

The composition of comets earned them the nickname 'dirty snowballs'

The icy relics of the solar system are composed of rock, gravel, dust, and frozen molecules, such as carbon dioxide, carbon monoxide, methane, ammonia, and water. Once close to the sun, these compounds sublimate into gases, creating a fuzzy cloud that earned the comets another nickname in history: hairy stars.

Defending Earth against asteroids

This three-minute video overview explains NASA's ambitious test to slightly alter the course of an asteroid by slamming a fast-moving space probe into its surface. Scientists hope to one day, if needed, use the technique to protect Earth from an asteroid impact.

Astrobiology is the study of life's origins and the search for life beyond Earth

The field incorporates observational missions to find and classify exoplanets—planets orbiting stars besides the sun—the probing of Earth's most extreme environments to learn what conditions allow life to exist, and theoretical and lab work to identify and analyze potential biochemical signatures.

NASA's Stardust mission collected and returned samples from a comet

Launched in 1999, the spacecraft traveled to comet Wild 2 and captured more than 10,000 dust particles from its coma using a tennis racket-like mesh covered in aerogel. It also took pictures of the comet before returning to Earth and releasing the collection canister during its 2006 flyby.

Earth is constantly bombarded by material from space

Most of this matter is composed of small particles, with any smaller than 33 feet in diameter burning up in the atmosphere. Larger asteroids can reach the ground, and those larger than several thousand feet cause global damage, including earthquakes and tsunamis.

The 'Celestial Police' accidentally discovered asteroids while planet hunting

The group was formed in 1800 to find a planet some astronomers believed existed between Mars and Jupiter. Prior to their disbanding in 1815, the group instead discovered Vesta, Juno, and other objects they would call asteroids.

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.

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.

Mold growth in space raises the hypothesis of life being brought to Earth

Panspermia suggests that life could be carried throughout the cosmos by asteroids, comets, and other objects, but it requires organisms that can withstand the extreme cold of space travel, stellar radiation, lack of water, and intense heat of planetary impacts. The discovery of mold on the International Space Station and experiments showing it can withstand radiation in outer space-like conditions increase the plausibility of the hypothesis.

Scientists can determine Earth's past environmental conditions by analyzing sediment cores—accumulated layers of mud and remains of charcoal, pollen, plants, algae, and other organic material.

Simulate asteroid impact, mitigation, and defense scenarios

Tens of thousands of asteroids are in orbit in our solar system, and only a fraction come close enough to concern humanity. This simulator allows you to see the big picture scenarios of an asteroid impact, strategies to mitigate its destruction, and how Earth could defend itself.

Only 40% of city-destroying asteroids have been detected

Statistical modeling shows that while we have identified the majority of extinction-level asteroids, smaller asteroids that can cause significant damage remain elusive. Some asteroids, like the one that exploded over Chelyabinsk in 2013, can't be detected ahead of time since they come from the sun's direction.

NASA's Near-Earth Object Surveyor can detect asteroids coming from the sun

Telescopes directed at the sun or lacking heat shields may become damaged, limiting our ability to monitor potentially dangerous objects coming from that direction. The NEO Surveyor is built to overcome this problem and spot asteroids that reflect as little as 5% of incoming light.

In 2013, an asteroid was named after Wikipedia

A main-belt asteroid previously labeled 274301 was renamed "Wikipedia" by the Committee for Small Body Nomenclature. First observed in 2008 by astronomers at the Andrushivka Astronomical Observatory, the asteroid was renamed based on a suggestion from a member of the Wikimedia Foundation in Ukraine.

One man in Arizona works to defend Earth from catastrophic space rocks

David Rankin, an observer and operations engineer at the NASA-funded Catalina Sky Survey, spends his days scanning for solar system objects that could collide with our planet. The job requires employees to work long shifts to help prevent asteroids from destroying our planet.

The oldest DNA recovered so far is 2 million years old

The oldest DNA recovered so far is about 2 million years old and has given scientists an unadulterated peek into ancient history. This nine-minute video explores the findings and implications of the DNA, which was pulled from frozen soil in...

Read the academic article explaining how ancient smells can be dissected and recreated

This paper explores how biomolecular data on past scents can be teased out and then transformed into olfactory museum experiences, adding another component to our understanding of archaeology.

About 99% of Earth's atmosphere is made of nitrogen and oxygen

At 78% and 21% respectively, the two elements are followed by argon with almost 1%. Trace amounts of other molecules, including greenhouse gases such as methane and carbon dioxide, and particulate matter such as dust and pollen, make up the remainder of the atmosphere's contents.

Peptides may have predated ribosomes—the cell's protein factory

Some scientists have hypothesized that peptides and RNA molecules may have coevolved as a single, mixed "chimeric" molecule, fueling the beginning of protein production and predating a primitive version of the ribosome. All life today uses ribosomes to make peptides. (Some users may experience a paywall.)

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.

A particle accelerator allowed researchers to noninvasively examine a mummy

The mummy hailed from the Faiyum oasis, where Egyptian and Roman cultures intersected, and was analyzed using the Advanced Photon Source at Argonne National Laboratory. The device used high-energy X-rays to probe the material composition of numerous objects embedded deep inside the mummy without damaging its remains.

NASA's DART mission successfully deflected an asteroid

The Double Asteroid Redirection Test crashed into asteroid moonlet Dimorphos in 2022, altering its orbital radius. The project required precise astrodynamics to strike the moonlet from 11 million kilometers away while traveling 22,530 kilometers per hour.

Scientists have tested atmospheric models by firing rockets into the aurora borealis

Functioning like components of a CT scan, the missiles transmit signals that can be used to identify charged particles and electromagnetic currents in slices. The slices are then combined to construct a computer-based model of Earth's atmospheric structure, which is used to compare the accuracy of physics-based models.

Watch visualization of different-sized asteroid impacts

The animations range from a 4-meter-wide asteroid that would burn up in the atmosphere with the impact of 0.6 Hiroshima nuclear bombs to a 940-kilometer asteroid the size of the dwarf planet Ceres, which would produce a mass extinction event.

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.

Despite privacy risks, scientists are using DNA in the air to assess ecosystem health

While DNA in soil and water samples has long been used for such analyses, airborne DNA is being incorporated into such efforts to monitor individual species abundance, detect invasive species, measure biodiversity, and determine the success of conservation actions. Future work may include detecting attacks from biological weapons.

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.

Blood evolved many times over hundreds of millions of years

The earliest evidence of a blood-like substance comes from ancient arthropods, which appear to have had copper-based blood. In the 500 million years since then, some creatures have grown to rely on other variants, such as humanity's iron-based blood.

Why are archaeologists brewing ancient beers?

Archaeologists have managed to brew beer from yeast found inside jugs abandoned thousands of years ago. This article explores why scientists are recreating these ancient beverages and what they hope to learn. People have been drinking beer for...

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.

Searching for the history of cancer in ancient human bones

Nestled under archaeology lies bioarchaeology, which involves the study of bones, human or animal. This subfield recently birthed another field of study: paleo-oncology. Paleo-oncology looks for cancer and related biomarkers in bioarchaeological remains. This TED article explains how this nascent multidisciplinary field challenges the idea that cancer is modern.

In 2025, UK scientists began studying climate data from a 1.5-million-year-old ice core

The Antarctica sample will be melted and analyzed in Cambridge to learn about prehistoric environmental conditions. Researchers hope the ice core reveals how Earth's glacial cycles shifted dramatically around 800,000 years ago.