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

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.

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.

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.

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

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.

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.

A real-time 3D-explorer of the solar system

NASA's Eyes on the Solar System allows you to track all kinds of objects in space in real time, from observatories like the James Webb Telescope to all manner of comets and asteroids. Zoom in and out, read up on space missions, and see the solar system from a totally new angle with this incredible interactive site. Jump in here.

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.

In 2025, the European Space Agency created the first artificial solar eclipse in space when one spacecraft cast a shadow onto another spacecraft to enable observations of the sun's outermost atmosphere.

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.

Over a decade before the launch of the Hubble Space Telescope, Nancy Roman oversaw the Orbiting Solar Observatory program, which launched eight spinning spacecraft into low Earth orbit to study the sun.

Explore an interactive solar system with 3D visualizations of meteor showers—streams of dust-like debris left behind from comets or asteroids that burn up in Earth's atmosphere.

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.

Because the retina lacks pain receptors, during a solar eclipse, those watching without protective eyewear may suffer from permanent damage without realizing it.

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.

Learn about the Parker Solar Probe, which 'touched' the sun in 2021

Launched in 2018, the probe is named after Eugene Parker, who predicted the existence of the solar wind in the 1950s. The probe's carbon-composite shielding has protected it from significant solar radiation as it has traveled through the sun's corona—the outermost layer of its atmosphere—though it will never reach the sun's surface during successive flybys.

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.

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.

Explore a series of NASA visualizations tracking satellites and space debris

The series illustrates the population of objects orbiting Earth as of February 2024, using data from US Space Command. These include active satellites, defunct spacecraft, rocket bodies and debris fragments larger than roughly 10 centimeters in low Earth orbit.

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.

The next generation of space-based observatories

How exactly does a space telescope come to be funded by NASA? NASA's most famous telescopes, like Hubble and James Webb, were once featured in the decadal survey–a once per decade survey run by the National Academy of Science that recommends which projects to support. This article and podcast covers which telescope designs are in contention to be part of NASA's next generation of space-based observatories.

A composite of telescope images of the sun, which each reveal unique solar features

While traditional cameras can reveal sunspots—cooler regions on the sun's surface—in visible light, x-ray detectors can highlight explosions of high-energy plasma and magnetic fields known as coronal mass ejections. Hydrogen-alpha filters can reveal clouds and filaments of material suspended in magnetic fields above the sun's surface.

Learn about solar neutrinos—about 70 billion of which pass through your thumbnail every second

About 100 quadrillion sextillion (10³⁸) of these elusive particles are created in the core every second, making up about 1% of the sun's total energy output. Because they seldom interact with normal matter, highly specialized equipment is needed to detect them, allowing scientists to probe what is happening in the solar core.

The majority of exoplanets—planets outside the solar system—have been discovered through mini-eclipses created when they pass in front of their host star and block some of its light from reaching Earth.

The Nancy Grace Roman Space Telescope—the first major NASA space telescope named after a woman—is expected to survey 12% of the sky in 17 months, a feat that would take the Hubble Space Telescope over a thousand years.

Inside the James Webb's amazing sun shields

The Webb team has stationed its mammoth observatory in solar orbit—and brought its instruments below 40 kelvins (minus 233 ºC). Remarkably, most of the cooling has been done passively, by shielding the telescope from the sun and letting physics take care of the rest.

View historical records of solar observations and discoveries, from telescopes in the early 1600s revealing sunspots to NASA's Parker Solar Probe photographing the sun from within its outer corona in 2025.

Variations in the energy of light force the use of multiple telescopes

Just as Earth's atmosphere allows the sun's visible light to pass through while blocking other harmful radiation, telescope mirrors and other optics can only reflect, absorb, or transmit certain types of light. Detectors also utilize semiconducting materials that react to specific energies of light, thereby preventing a one-telescope-fits-all solution.

Webb's sunshield enables extreme cooling for precision space observation

To avoid interference from its own heat, the telescope uses a five-layer shield to stay ultra-cold and stable, allowing its instruments to function at cryogenic temperatures. One instrument, MIRI, gets so cold it needs a helium-powered cooler to reach just 7 Kelvin, or -447°F.

View media of the sun's south pole, taken for the first time in 2025

Captured in March 2025 by the Solar Orbiter—a satellite developed by ESA and NASA—the images and video are the first to be taken by an object not moving around the sun's equator. The orbiter moved outside the plane of the planets by using Venus to slingshot it into a tilted orbit, and the data it collected will help scientists better understand the sun's magnetic activity.

NASA's guide to solar flares and how they work

Flares happen when the powerful magnetic fields in and around the sun reconnect. They're usually associated with active regions, and carry the potential to disrupt electronics on Earth.

Eclipse glasses protect the eyes from overexposure to the sun's ultraviolet, blue, and infrared light, as a person's instinct to look away from the sun is diminished when it's partly blocked.

Excluding using another planet's gravity to redirect the object, it takes less energy for a spacecraft to leave the solar system than to hit the sun.

Solar eclipses are a cosmic coincidence because the moon is 400 times smaller than the sun but about 400 times closer to Earth, allowing it to block sunlight for those on Earth within its shadow.

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.

A solar eclipse viewer can be made from everyday objects, such as a cereal box, aluminum foil, tape, and paper, to safely view the cosmic event.

A map of every object in our solar system

The infographic from 2020 illustrates the complexity of our solar system, mapping over 18,000 objects including asteroids, comets, planets, and moons. Created by biologist Eleanor Lutz using data from NASA, it shows the non-linear distribution of objects due to the sun's gravitational pull. Objects nearer to the sun are more numerous, forming tighter orbits, while those farther out are fewer and more widely spaced.

During Nancy Roman's tenure as the agency's chief of astronomy, NASA launched Stargazer—the first successful space telescope—as part of the Orbiting Astronomical Observatory program.

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.

How scientists study Earth's geocorona, the farthest portion of the planet's exosphere

Seen via ultraviolet radiation scattered by neutral hydrogen in the region, observations by the ESA/NASA Solar and Heliospheric Observatory indicate that the geocorona extends roughly 50 times Earth's diameter above its surface. At this distance, the geocorona extends beyond the Moon's orbit.

Learn about the sun's corona, which is nonlethal despite a temperature of millions of degrees

The outermost layer of the sun's atmosphere is best seen during a solar eclipse, when the moon blocks the much brighter (and significantly cooler) solar surface. Despite the high-energy particles in the corona moving fast enough to escape the sun's gravity and gradually become solar wind, their density is too low to contribute meaningfully to the region's overall radiation.

Find which comets are currently visible in the night sky

Incorporating sightings reported in the Comet Observation database and information from NASA's Jet Propulsion Laboratory, this list provides a finder chart, star map, tracker, simulated orbit, and key properties for each comet, all viewable based on a user's input position on Earth.

Explore an interactive visualization of the solar system

This tool allows you to view the orbits of planets, dwarf planets, moons, asteroids, and other significant objects in the solar system. Clicking on an object reveals key facts and historical data.

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.

View photographs of solar eclipses on Mars, Jupiter, and Saturn caused by the moons of these planets blocking sunlight.

Read about the dangerous comet behind the Perseids meteor shower

Every summer, Earth passes through the debris trail of the Swift-Tuttle comet, producing the spectacle of the Perseids meteor shower. The phenomenon is a glorious opportunity for amateur stargazers, but astronomers have long noted the comet's orbit...

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.

An exoplanet detection method involves measuring a host star's auroras

Astronomers have reported indirectly identifying a planet by observing its debris interacting with the magnetic field of the star it orbits. The interaction is a larger-scale version of the auroras observed on Jupiter, which are produced when material released by its moon, Io, interacts with the gas giant's magnetic field.

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.

Gaming out how our solar system might catch a new planet

If Pluto's downgraded status to a dwarf planet has got you down, consider this: Scientists think there's a chance our solar system could catch a new planet. The first ever observed so-called Interstellar Object was reported in 2017, a reddish, cigar-shaped rock astronomers named Oumuamua. Although it left in 2022, scientists believe an object with the right mass and trajectory might take a seat at the planetary table. Learn how it would work here.