Planetary defence
The only natural disaster humanity could, in principle, prevent entirely — and the only one where the whole job is finding things early enough. This is where that effort stands today.
Where things stand right now
2,204
objects monitored
orbits not yet precise enough to exclude any impact
0
above Torino 0
the scale's own definition of anything but routine
358
first observed in 60 days
and since given a computed orbit — not the same as newly announced
122
awaiting confirmation
candidates on the MPC's page right now
What the system actually does
Find. Survey telescopes sweep the sky nightly for moving points of light. Almost everything they find is already known; the rest goes to the Minor Planet Centre, which collates observations from observatories worldwide and publishes candidates for others to follow up.
Track.Once enough observations accumulate, an orbit can be fitted. The uncertainty in that fit is the whole game: a week's arc leaves an object's position a year hence uncertain by millions of kilometres, and a decade's arc pins it to a few hundred.
Assess. Sentry projects every fitted orbit forward and flags any that cannot yet be shown to miss. The 2,204 objects on that list are there because of what is not yet known about them, and they leave it as observations accumulate.
Deflect.Demonstrated once, in 2022, by NASA's DART mission. The encyclopedia covers what was done and what it showed; this page's job is the live figures above.
The full account
This page is the live status and nothing else. AsteriaStar already covers planetary defence properly in two places, and repeating either here would give the platform three accounts of one subject that drift apart. The survey programmes, the deflection techniques and their trade-offs, the coordination structures and the impact record are in the encyclopedia — 14 catalogued entries — and the asteroid section covers the objects themselves. The hazard scales are defined there too; this page and the risk pagequote them only as far as reading today's numbers requires.
- Planetary defence encyclopedia →
Surveys, deflection methods, coordination and the impact record.
- Asteroid defence overview →
The asteroid section's own account, including the hazard scales in full.
- Asteroids →
The objects themselves: families, groups, near-Earth classes and named bodies.
What this page will not do
It will not tell you an asteroid is coming. If one ever were, the announcement would come from the agencies that compute these orbits, not from a website reading their tables — and it would appear in the Sentry figures above before anywhere else.
It also will not compute a risk of its own. Every hazard figure on these pages is JPL's, on a scale JPL or the IAU defined, quoted with the caveats they attach to it. A platform that invented its own asteroid danger rating would be manufacturing authority it does not have, about a subject where alarm is cheap and accuracy is not.
Every figure here is JPL's or the Minor Planet Centre's. AsteriaStar computes no impact probability and applies no danger rating of its own: where a hazard is named, it is on a scale the issuing agency defined, quoted as they define it. A close approach is described by its distance and its uncertainty, because that is what the data says. Objects pass within a few lunar distances routinely, and the word for that is “routine”.
Sources & references
The primary and reference sources this topic draws on.
- NASA JPLJet Propulsion Laboratory / Solar System Dynamics
Orbital data, ephemerides, and small-body parameters for planets, asteroids, and comets.
- NASANational Aeronautics and Space Administration
Mission data, planetary science, space telescopes, and public-domain imagery.
Most NASA-produced imagery is in the public domain; individual items are checked for usage terms before publication.
- Minor Planet CenterIAU Minor Planet Center
Designations and orbits of asteroids, comets, and minor bodies.