Close doesn’t mean collision
Distances in the explorer are measured from Earth’s centre. One lunar distance (LD) is about 384,400 km. The Apophis feature above uses height above the surface instead.
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99942 Apophis
2029 flyby · distance guide
🛡️ 2029 flyby · no Earth impact
A rare close encounter with a roughly 340-metre asteroid. Apophis will pass inside the altitude of geostationary satellites, giving researchers an exceptional opportunity to study it.
~340 m📏 Mean diameter
~32,000 km🌍 Above Earth’s surface
13 Apr ’29📅 Encounter date
NASA’s 2021 orbit analysis ruled out an Earth impact for at least the following century.
📖 NASA’s Apophis guide ↗Feature reviewed 2 October 2026 · encounter date shown without a precise local time.
Where and when? Approximate flyby guide
Map labels use UTC on 13 April 2029. Teal shading combines approximate dark-sky opportunities across the sampled hours. Larger dots mean closer to Earth, not a larger asteroid. This is a rough guide, not a guaranteed naked-eye viewing area.
| Event | UTC - 13 April 2029 | Your local time | Height above surface |
|---|---|---|---|
| Enable JavaScript for local times; the map uses UTC. | |||
🪨 S-typeStony asteroid with silicates, nickel and iron
⏱️ ~31 hEnd-over-end rotation
🔭 ~450 mMinimum long axis
🌍 Earth-crossingAten now · Apollo after 2029
🛰️ OSIRIS-APEXFollow-up mission after the flyby
🌊 Tidal reshapingEarth gravity may trigger surface changes
✨ More about the 2029 encounter
Apophis was discovered in 2004 and briefly appeared to have possible 2029, 2036 or 2068 impact scenarios. Better observations ruled those out. During the flyby, Earth’s gravity will pull, twist and stretch the asteroid and slightly change its orbit.
NASA says this will be the closest known advance-observed pass by an asteroid of this size. NASA Apophis facts ↗ · OSIRIS-APEX ↗
Object explorer
Next 100 years · within 0.2 AU (~78 LD) · close ≠ impactLoading current object dataChecking NASA/JPL records…
Type
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Palermo cumulative
🌍 Earth impact history
Selected major impacts & airbursts · sizes are estimatesLoading catalogue…
Dates use years ago (Ma in source tables means million years ago); ± shows the source’s stated uncertainty. Default order: most recent first. Flags show present-day locations. A curated selection, not a complete ranking. Ancient dates and sizes are rounded source estimates; crater erosion and different models limit comparisons. These past events have no present-day Torino rating.
ⓘ Understanding distances, hazards and uncertainty
What does “hazardous” mean?
A potentially hazardous asteroid meets orbit-proximity and brightness criteria. That classification alone is not a prediction of an impact.
CNEOS definitions ↗Read the uncertainty
Sentry monitors possible future impacts allowed by uncertain orbits. A listing is not a forecast of a collision. Further observations can remove an object from the list.
How Sentry works ↗🔭 Observing an object
This page does not yet calculate visibility for your location. Absolute magnitude H cannot tell you whether a target is visible to the naked eye or through a telescope. Use JPL Horizons for apparent magnitude and sky position at your chosen place and time.
Open JPL Horizons ↗Data coverage and sources
Close approaches: NASA/JPL CAD, near-Earth asteroids and comets only, over a rolling 36,525-day window (approximately 100 years) within 0.2 AU. Rows represent encounters, so an object can appear more than once. Known diameters are shown when supplied; unknown sizes are not inferred from brightness. Encounter times default to your browser’s local zone. The toggle also offers UTC and original TDB. UTC conversion subtracts an approximate 69.184 seconds from the source Julian date, using the current leap-second count; update the conversion if a future leap second is announced. Millisecond periodic terms are omitted. Display is to the minute. Fetch timestamps remain browser-local.
Impact monitoring: NASA/JPL Sentry summary data, sorted by highest cumulative impact probability by default. Probabilities cover the listed potential-impact year range, not a single encounter. Sentry diameters are approximate and often estimated from brightness. This page is not an exhaustive catalogue or an emergency alert service.
🌍 Historical catalogue & size estimates
Each history row links to its NASA or ESA source. The expanded catalogue includes a NASA-hosted Earth Impact Database reference table. Those entries retain that table’s reported ages and uncertainties and may not reflect subsequent research revisions. Object sizes are estimates, not measured surviving rocks; an airburst may leave no impact crater. A missing value means this catalogue does not provide a supported estimate. Sorting object size uses the lower endpoint of a published range or lower bound, so it is not a definitive ranking.
Open the JSON catalogue ↗📖 Impact monitoring glossary · scores & probability
Torino score: a public-facing scale from 0 to 10 combining impact likelihood and potential damage. The table shows the highest score across an object’s possible impact scenarios. It is not a percentage.
Torino 0: negligible collision likelihood, or a small object unlikely to cause significant damage. It does not always mean exactly zero probability. An object can remain on Sentry’s watchlist while its possible orbits are studied.
⚪ 0: no hazard · 🟢 1: normal · 🟡 2–4: astronomer attention · 🟠 5–7: threatening · ❗ 8–10: certain collision, with increasing consequences.
Unrated: no valid Torino score was supplied. The scale applies to potential impacts within 100 years; farther-future cases may be unrated. Unrated does not mean zero risk or a higher risk level.
Chip counts: the small number beside a filter is how many objects would match that option with your other filters. A count of 0 means no matching objects, not a Torino score of zero.
Who calculates the probability? NASA/JPL’s Sentry system calculates it from telescope and radar observations. SpaceOpsLab displays JPL’s published result.
Why isn’t it certain? We know the asteroid exists, but its exact orbit is never measured perfectly. Several future paths can fit the observations; some may intersect Earth. Sentry estimates how likely those impact paths are, accounting for measurement uncertainty.
What improves the estimate? More precise observations, especially over a longer time span, narrow the possible paths. A possible impact can then be ruled out—or its probability can rise. Size mainly affects the consequences of an impact; the path and arrival time determine whether a collision occurs.
Probability in this table: the combined chance of impact across the listed potential years, based on the current observations and models.
💥 What could an impact do?
The labels beneath diameter are broad size-based context, not calculated outcomes. Small asteroids often break up in the atmosphere; larger ones can cause local or regional devastation, and kilometre-scale impacts may have global atmospheric effects. Composition, speed, entry angle and impact location matter. Palermo combines probability, impact energy and time—it cannot label an object a “city killer”.
🔮 How far ahead can impacts be predicted?
Sentry routinely searches the next 100 years for possible impacts. Some well-studied objects can be analysed farther ahead, but confidence depends on the observations and how uncertainty grows through future encounters. A long forecast does not mean a collision is likely.
How JPL assesses uncertainty ↗