What's Flying By Earth Right Now
A Near-Earth Object is any asteroid or comet with an orbit that brings it within 1.3 AU of the Sun — roughly 194 million km — which means it can come within striking distance of Earth. Most are completely harmless; they fly by at distances of millions of kilometres and we never notice. But the catalog now contains 38,000+ known objects, and new ones are discovered daily. The question planetary scientists care about is not "are any coming?" — they always are — but "are any of the ones we haven't found yet on a collision course?"
Live Close Approach Feed
Objects approaching within 0.05 AU (~7.5 million km) of Earth over the next 7 days, sorted by closest approach date. Data via NASA NeoWs API.
Upcoming Earth Close Approaches
● Live Next 7 daysThe Torino Scale — How We Rate the Risk
When a new NEO is discovered, its trajectory is calculated and assigned a Torino Scale value — a communication tool combining impact probability and energy release into a single 0–10 number. Almost every newly discovered object starts at 0 and stays there. A non-zero rating is genuinely rare and always temporary — more observations almost always refine the trajectory and drop it back to 0.
When Rocks Actually Hit — Notable Events
The threat isn't hypothetical. Earth is hit by objects constantly — most burn up harmlessly. The ones that don't are a reminder of why this work matters.
An asteroid or comet fragment roughly 50–80 metres in diameter exploded 8–10 km above a remote Siberian forest with the force of 10–15 megatons — roughly 1,000 times the Hiroshima bomb. It flattened an estimated 2,000 km² of forest, knocking down 80 million trees. Had it arrived 4 hours later, it would have hit St. Petersburg. No crater — it was an airburst. The most powerful impact event in recorded history.
A 20-metre asteroid entered the atmosphere at 60,000 km/h and exploded over Chelyabinsk with 30× the energy of the Hiroshima bomb. The shockwave shattered windows across six cities, injured 1,500 people (mostly from flying glass), and damaged 7,200 buildings. It wasn't detected before impact — it came from the direction of the Sun. Every existing survey telescope was pointing the other way. Detection time: 11 minutes after it entered the atmosphere.
When discovered in 2004, the 370-metre Apophis was briefly rated Torino 4 — the highest in history — with a 2.7% chance of hitting Earth in 2029. Further observations dropped the 2029 probability to essentially zero, but a 2036 and then 2068 concern lingered for years. As of 2021, radar data confirmed Apophis will pass Earth on April 13, 2029 at just 32,000 km — closer than geostationary satellites. Safe. But it will be visible to the naked eye, and spacecraft are being planned to study it during the flyby.
A 40–90 metre asteroid briefly reached Torino Scale 3 in January 2025 with a ~3% impact probability for 2032 — the highest probability for an object of its size ever recorded. For two weeks it was the most closely watched asteroid in history. By February 2025, additional observations refined its orbit and it was dropped to Torino 0. It illustrated both how the system works and why early detection is so critical — finding objects years or decades out gives time to act.
The 10–15 km asteroid that ended the Cretaceous. Impact energy: roughly 1 billion Hiroshima bombs. Created a 180 km crater under the Yucatán Peninsula. Ejecta blocked sunlight globally for years, killing ~75% of all species including non-avian dinosaurs. This scale of impactor — the kind that causes mass extinctions — is extremely rare and we've catalogued essentially all of them. None are on course for Earth.
NASA's DART spacecraft deliberately crashed into the asteroid Dimorphos at 6.6 km/s in September 2022, shortening its orbital period by 32 minutes — 25× more than the minimum needed to count as a success. It was the first time in history humanity intentionally and measurably changed the orbit of a celestial body. Planetary defense is no longer theoretical.
Planetary Defense — The Missions
DART — Double Asteroid Redirection Test
Launched November 2021. Impacted Dimorphos (moonlet of asteroid Didymos) September 26, 2022. The 570 kg spacecraft hit at 6.6 km/s, and the resulting orbital change — measured precisely by ground-based telescopes — exceeded predictions by 25×. The success validated the kinetic impactor technique as a viable planetary defense method. DART's impact site was later imaged by ESA's LICIACube flyby satellite, revealing a double-tail debris plume.
DART Mission ↗
Hera — Europe's Post-Impact Inspector
Launched October 2024. Arriving at Didymos/Dimorphos in 2026. Hera will perform a detailed post-impact survey of the DART crash site — measuring the crater, Dimorphos's internal structure, mass, and the precise momentum transfer from the impact. This data will calibrate models for future deflection missions, making the next one far more predictable. Hera carries two CubeSats (Milani and Juventas) that will descend to the surface and conduct radar and spectrometer surveys.
ESA Hera ↗
NEO Surveyor — Closing the Detection Gap
The single most important near-term tool for planetary defense. NEO Surveyor is an infrared space telescope designed to detect asteroids that are difficult or impossible to find from the ground — particularly objects approaching from the Sun's direction (like Chelyabinsk). It aims to catalogue 90% of all NEOs larger than 140 metres within 10 years. Congressional mandate from the George E. Brown Jr. Near-Earth Object Survey Act requires NASA to achieve this by 2033. NEO Surveyor is the instrument designed to get there.
NEO Surveyor ↗
Apophis 2029 — The Flyby of the Century
On April 13, 2029, the 370-metre asteroid Apophis will pass Earth at 32,000 km — closer than our geostationary satellites, and visible to the naked eye from Europe, Africa, and western Asia. It will be the largest asteroid to pass this close in recorded history. Multiple missions are being planned to study it during approach and flyby, turning a once-feared threat into an extraordinary science opportunity. NASA's OSIRIS-APEX (formerly OSIRIS-REx, now en route) will rendezvous with Apophis shortly after its Earth flyby.
Lagrange Points — Cosmic Parking Spots
Lagrange points are positions in space where the gravitational pull of two large bodies — say, the Sun and Earth — precisely balances the centrifugal force felt by a smaller object. At these points, an object can orbit in a stable or semi-stable position relative to the two larger bodies without expending fuel. There are five for any two-body system; the Sun-Earth Lagrange points are directly relevant to NEO science and planetary defense.
L1
Ideal for solar monitoring — spacecraft here have an unobstructed view of the Sun at all times. SOHO, ACE, DSCOVR, and the Solar Orbiter use this point. Space weather warnings (solar flares, coronal mass ejections) that protect satellites and power grids originate here. Also theoretically useful for early warning of objects approaching from the Sun's direction — the blind spot that caught Chelyabinsk.
L2
The premier location for space observatories. JWST, Gaia, Planck, and Herschel all orbit L2. With Earth's disc blocking the Sun, instruments stay cold and shielded. JWST's extraordinary infrared sensitivity — which enables exoplanet atmosphere detection and early universe imaging — is only possible from L2. Not relevant to NEOs directly, but foundational to the telescopes that study them.
L3
The least useful Lagrange point for practical purposes — permanently hidden behind the Sun, communication is impossible without relay satellites. Science fiction's "counter-Earth" lives here. In practice, L3 is gravitationally unstable on long timescales and no missions use it.
L4 & L5
Directly relevant to NEO science. L4 and L5 are stable equilibrium points — objects placed here stay there for billions of years. Jupiter's famous Trojan asteroids cluster at its L4 and L5. Earth also has Trojans: as of 2024, several confirmed Earth Trojan asteroids have been found at our L4/L5. NASA's Lucy mission is currently en route to study Jupiter's Trojans. Future proposals suggest L4/L5 as potential staging points for deflection spacecraft — stored close to Earth but out of the way, ready to launch on short notice.
Who's Watching — Detection Networks & Resources
Catalina Sky Survey (CSS)
One of the most prolific NEO discovery programs in the world, operating telescopes from Mount Lemmon and the Catalina Station in Arizona. CSS has discovered more NEOs than any other survey program.
CSS ↗Pan-STARRS
Two 1.8-metre telescopes on Haleakalā, Maui, survey the entire visible sky multiple times per month. Pan-STARRS discovers hundreds of NEOs per year and provides crucial follow-up data for other surveys.
Pan-STARRS ↗ATLAS
Asteroid Terrestrial-impact Last Alert System — designed for short-warning-time detection. Four telescopes scan the sky nightly and can provide 1-hour to 3-week warning for impactors ranging from 20-metre city-killers to 100-metre regional destroyers.
ATLAS ↗Sentry / CNEOS
NASA's automated collision monitoring system. Sentry continuously scans the known NEO catalog for any that have a non-zero impact probability over the next 100 years. The public table updates daily — anyone can check.
Sentry ↗ESA Risk List
The European Space Agency's independently maintained catalog of objects with non-zero impact probabilities. Running it alongside Sentry provides a cross-check — any object that appears on both lists gets immediate attention from the international community.
ESA Risk List ↗Minor Planet Center (MPC)
The official worldwide repository for positional measurements of minor planets, comets, and outer solar system objects. Operated by the IAU under NASA funding. Every new NEO discovery is reported here first — the international clearing house for the entire field.
MPC ↗Vera C. Rubin Observatory (LSST)
The Rubin Observatory in Chile began its Legacy Survey of Space and Time in 2025 — imaging the entire southern sky every three nights. Expected to roughly double the number of known NEOs within its first year of operations, particularly in the harder-to-detect size ranges.
Rubin Observatory ↗NEO Surveyor (Launch ~2027)
The next major leap in detection capability — an infrared space telescope purpose-built to find dark asteroids that ground surveys miss. Designed to achieve the congressional mandate of cataloguing 90% of PHAs larger than 140 metres within 10 years of launch.
NEO Surveyor ↗Explore Related
The solar system context, active missions, and what's launching to study and defend against these objects.
Solar System Explorer → Active Missions → Future Missions →