NASA's DART mission successfully deflected an asteroid

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.

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.

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.

What would happen if a massive asteroid struck Earth?

While NASA states that no known asteroid currently threatens Earth, past impacts demonstrate that the risk is real. The agency has tested deflection technology to alter an asteroid's path, as this visualization imagines a worst-case collision scenario.

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.

The Artemis program to bring humans to the moon for the first time since 1972

Using NASA's next-generation megarocket, the Space Launch System, Artemis I will take an uncrewed spacecraft on a 42-day journey around the moon. Subsequent missions plan to land the first woman on the lunar surface.

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.

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.

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.

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.

Craters found on the moon and the calculated dates of these impacts, based on rocks returned by the Apollo missions, suggest that Earth was pummeled by asteroids for millions of years—a period known as the Late Heavy Bombardment.

Mar's moons, Phobos and Deimos, are thought to be captured asteroids

Of the two Martian moons, Phobos orbits more quickly, completing three revolutions a day. It gets 1.8 meters closer to Mars every year, and may crash into the planet in about 50 million years.

By measuring radio signals transmitted to and received from distant spacecraft, NASA's Deep Space Network can determine a spacecraft's position and speed and send commands to alter its trajectory.

Congressional funding for asteroid detection has long seen bipartisan support

Although asteroid detection is mandated by law, the NEO Surveyor telescope, which is specifically designed to detect asteroids, received more than twice the funding requested by NASA in 2023.

Lasers could be the most cost-effective tool for clearing dangerous space debris

A NASA study found that lasers from ground- and space-based systems could utilize the momentum of light to safely push smaller debris out of their orbits. These systems would need to be accompanied by amendments to international space law, which prevents any nation from touching debris from another country, among other strategies.

By 2028, a space trash-avoiding maneuver is expected to occur every 18 seconds

As the number of active Starlink satellites increases, greater efforts will be required to keep low Earth orbit free of debris, sparking a new technological space race. NASA has found that using lasers to manage small and medium debris could save up to $9B over 30 years.

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.

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.

A lunar probe’s crash landing may have spilled tardigrades onto the moon

In 2019, Israel’s Beresheet probe, which contained tardigrades in a cryptobiotic state, underwent a gyroscopic failure when attempting to land. If they survived the crash, the tardigrades may have spread across the lunar surface, raising ethical concerns about planetary contamination.

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.

The crew of Artemis II captured a photograph of Earth setting as they orbited the moon

On April 6, 2026, the Artemis II astronauts captured a striking image of Earth setting as their spacecraft orbited the Moon, echoing the iconic Earthrise photo taken by Apollo 8's Bill Anders 58 years earlier.

Ballistic experiments show that tardigrades are unlikely to be an alien species

Those fired from guns at speeds as high as 825 meters per second (1,845 mph) could be resuscitated after impact. Shock pressure from greater speeds tore apart the samples, suggesting they could not survive asteroid impacts if brought to Earth from outer space.

NASA uses a specialized plasma wind tunnel to test heat shield technology

The ArcJet Complex ionizes compressed air that fires onto shields at hypersonic speeds, replicating the conditions of high-speed, planetary reentry. An enhanced facility incorporates lasers to mimic the radiant heating experienced during high-energy atmospheric traversal.

Ahead of constructing a lunar base as part of the Artemis program, NASA will send a fleet of hopping drones to scout the moon's south pole.

Why are we finally returning to the moon after 50 years?

After 50 years, NASA is heading back to the moon. Artemis missions will push beyond Apollo, landing astronauts on the moon's south pole by 2027. But why the long wait? Budget cuts, shifting priorities, and outdated tech stalled lunar exploration—until now. With new goals and modern tech, NASA is ready to return.

A lunar 'satellite catapult' revives a 50-year-old idea for launching rockets

Elon Musk has proposed building a mass driver on the moon to fling satellites into space, exploiting low gravity to cut fuel and costs. The concept dates to 1970s space-settlement studies, highlighting how older industry ideas are resurfacing amid today's AI and space-infrastructure race.

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.

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.

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.

The accidental birth of radio astronomy and the benefits of a moon-based telescope

Detecting radio waves from distant celestial objects is complicated by noise from solar wind, which the nighttime side of the moon is shielded from. If lunar temperature extremes can be overcome, the environment may serve as an optimal future home for radio astronomy, a field that began in 1928 when a 30-meter-long directional antenna, mostly out of brass and wood, picked up signals from the Sagittarius constellation.

A gallery of shots taken during the lunar flyby of Artemis 2

On April 6, 2026, the four-person Artemis 2 crew took photos of "earthset" and "earthrise" from the Orion spacecraft window during their lunar flyby. It was the first time humans had flown around the moon in over 50 years.

Because seismic waves travel 100 times faster than tsunami waves—waves typically travel faster through solids than liquids—measurements of geological activity help tsunami detection systems provide early warnings.

Deep Impact was the first mission to probe beneath a comet's surface

The NASA mission sent a probe to deliberately crash into comet Tempel 1, producing an explosion equivalent to 4.7 tons of TNT. The payload included a compact disk with more than 625,000 names of people who participated in the "Send Your Name to a Comet!" campaign.

Simulations show unidentified asteroids around Venus may pose a threat to Earth

A new study suggests that Venus' co-orbital asteroids—space rocks that lag ahead or behind the planet—could potentially destroy cities if they strike Earth. While no observed co-orbitals currently pose a threat, observational bias prevents observation of those of greater risk.

NASA was founded in response to early Soviet space achievements

Although starting behind in the Space Race in 1958, NASA became a global leader in humanity's exploration of space with the Apollo program, which placed astronauts on the moon. Since then, it has been responsible for the construction of multiple telescopes, the International Space Station, and development of the Artemis program to return humans to the Moon before eventually reaching Mars.

The Polaris Dawn was a privately crewed spaceflight

SpaceX's Crew Dragon capsule Resilience spent five days in low Earth orbit as part of the first of three planned missions under the name Polaris Dawn. The historic journey took participants farther away from our planet than anyone has been since the Apollo missions.

The moon is moving 3.8 centimeters farther away from Earth each year

Driven by tidal forces, the effect is minimal and slow, ensuring stable tidal patterns and lunar cycles. Earth's rotation slows down as the Moon gains orbital momentum, slowly lengthening the day over time.

The next five asteroid approaches

Asteroids are zinging by our planet regularly, and some of them you can see without a telescope. Here's a regularly updated list of the next five asteroid approaches.

Simulating the moon's surface in the desert

And why is the next cohort headed there? The geological conditions in Flagstaff, Arizona, can easily echo those of the moon, making the area a prime spot to train astronauts. This article explains how scientists crafted these training grounds and why astronomers are drawn to the nearly century-old city.

Relive the Apollo 11 moon landing minute by minute

This interactive project lets you experience Apollo 11 in real time—listening to exchanges between the astronauts and NASA's Mission Control as they guided humanity's first journey to the lunar surface and safely home.

NASA's ESCAPADE mission will study Mars' atmosphere

The $80M mission—a collaboration between private companies, universities, and NASA—sent two copy machine-sized orbiters on a Blue Origin rocket to the red planet to study its magnetic field and atmospheric loss.

Space trash is making low Earth orbit increasingly dangerous for spacecraft

Millions of fragments from satellites, rockets, and other spacecraft that are no longer operational move thousands of meters per second as they circle Earth. Even a piece of debris a centimeter in size can cause mission-ending damage to space stations, telescopes, and astronauts.

A financial analysis of space trash cleanup strategies identified long-term benefits

Despite significant initial costs, a NASA report found that removing small debris would provide savings from preventing mission-ending damage, which would offset expenses within a decade. Financial benefits would also come from using less fuel for maneuvers to avoid collisions with debris.

The Polaris Dawn program led to the first commercial spacewalk

As part of the Polaris program, this first mission included a crew comprising astronauts and SpaceX engineers, who conducted scientific experiments and cultural outreach, such as raising funds for St. Jude Children's Research Hospital.

Explore a collection of moon interactives from NASA, including a 3D lunar surface explorer, a tool for classifying moon rocks, and an interactive map for observing the moon each day of the year.

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.

Scientists have proposed using lasers to push space trash into Earth's atmosphere

Such projects would allow most debris to burn up and no longer pose a risk to active satellites, telescopes, and astronauts on space stations. Enacting these plans would require substantial investments from private and governmental space agencies and overcoming international laws that prevent the removal of another country's space equipment.

Research suggests a 95-kilometer-wide (59-mile-wide) asteroid impact could boil the Earth's oceans

Even a 1-kilometer-wide (0.62-mile-wide) asteroid can trigger earthquakes and tsunamis on impact with oceans. The overwhelming majority of asteroids that reach Earth are much smaller and burn up in the atmosphere before reaching the ground.

Discovering how the dinosaurs went extinct may have helped avert nuclear war

This NPR Throughline episode explains how the 1980 discovery that an asteroid-driven dust cloud killed the dinosaurs inspired Cold War scientists' fears of "nuclear winter"—a sunlight-blocking aftermath of nuclear war that may have discouraged leaders from launching one.