Asteroids Passing Earth Today

Small bodies pass through Earth’s wider celestial neighborhood routinely. The live display above lists known asteroid and comet close approaches using calculations published by NASA’s Center for Near-Earth Object Studies (CNEOS) at the Jet Propulsion Laboratory. “Close” is an astronomical description: an object listed here can still pass hundreds of thousands or millions of kilometers from Earth.

The purpose of this page is to put those approaches in context. It is not a list of objects expected to hit Earth. Close-approach tables contain predicted trajectories for bodies that have already been observed, and the great majority present no impact threat during the listed encounter.

How to read a close approach

Closest-approach time is the calculated moment when the distance between the centers of Earth and the object reaches its minimum for that encounter. NASA/JPL’s close-approach API reports its calendar time in Barycentric Dynamical Time (TDB), the time scale used for the underlying orbital calculations. It differs from civil UTC by roughly a minute, so the local calendar date may also differ depending on where a reader lives.

Miss distance may be expressed in kilometers, astronomical units or lunar distances. One astronomical unit (AU) is the average distance between Earth and the Sun, about 150 million kilometers. One lunar distance (LD) is the average distance between Earth and the Moon, about 384,400 kilometers. The Moon’s orbit is not perfectly circular, so LD is a convenient standard unit rather than the Moon’s exact distance on a given day.

Relative velocity describes how quickly the object is moving with respect to Earth during the encounter. It does not mean that the object is moving directly toward the planet. An asteroid can pass at high relative speed while remaining safely distant.

Estimated diameter is often a range rather than an exact measurement. For many objects, size is inferred from brightness. That conversion depends on albedo—how much light the surface reflects—so a dark, larger body and a bright, smaller body can appear similarly luminous. Radar observations, thermal measurements or spacecraft visits can improve an estimate.

What is a near-Earth object?

A near-Earth object, or NEO, is an asteroid or comet whose orbit brings it into a defined region near Earth’s orbit. The classification describes orbital geometry, not an immediate danger. Most known NEOs never come especially close to Earth during the period in which their trajectories are calculated.

A potentially hazardous asteroid is also a technical category. It generally combines a minimum-orbit-intersection criterion with an estimated size threshold. The label identifies objects deserving sustained observation; it does not mean an impact is predicted. Risk assessment depends on the orbit and its uncertainty at particular future dates.

Why predictions sometimes change

An asteroid’s orbit is calculated from repeated measurements of its position over time. A newly discovered body may have a short observational arc and therefore a wider range of possible future positions. Additional observations usually narrow that uncertainty and improve the predicted pass time and distance.

Numbers may also change when old observations are remeasured, radar data become available or researchers account for small forces such as the Yarkovsky effect, in which uneven thermal radiation gradually alters an asteroid’s orbit. A revision is part of the normal process of orbit determination and does not necessarily indicate a newly increased risk.

Close approach versus impact risk

The CNEOS close-approach database answers the question, “Which known objects pass within a selected distance?” Impact monitoring is a different task. NASA’s Sentry system continuously examines the current asteroid catalog for possible future impacts over roughly the next century. An object can appear in a close-approach table without appearing on a risk table, and a newly discovered object can briefly appear on a risk table until more observations eliminate possible impact trajectories.

Very low initial probabilities often fall to zero as the orbit becomes better constrained. For risk questions, readers should consult the official NASA CNEOS Sentry system rather than interpreting miss distance alone.

What is not shown

The catalog includes known objects. Small asteroids can remain undiscovered until shortly before an approach, particularly when they arrive from the direction of the Sun or are too faint for earlier surveys. Small pieces of space rock enter Earth’s atmosphere frequently and generally burn up; the live table is not intended to catalog meteors or every natural object near the planet.

Methodology and sources

The live module queries the official JPL Small-Body Database Close-Approach Data API, which provides current close-approach data for asteroids and comets. Its records draw on orbit solutions in JPL’s Small-Body Database. ARGO.net selects a defined date and distance window, presents key fields and converts units where useful. We do not calculate independent trajectories.

Definitions and risk context are checked against NASA CNEOS information about near-Earth objects and NASA’s impact-monitoring documentation. A linked JPL record should be treated as the authoritative source for an individual object.

Limitations

• Approach circumstances are calculated values and can be revised as orbit solutions improve.
• Diameter estimates may have substantial uncertainty.
• The table covers known objects and is not a complete inventory of all nearby natural bodies.
• “Potentially hazardous” is a classification, not a prediction of impact.
• A temporary source or network problem may delay the displayed refresh.

Update log

• July 2026: ARGO Asteroids Passing Earth Today launched with NASA/JPL close-approach data and explanatory guidance on distance, size estimates and impact terminology.