SpaceAtlas Space Object Data
NASA JPL SBDB · 2021 AR2

2021 AR2

2021 AR2 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.261 AU it takes 1.42 yr to circle the Sun.

Apollo Observations: 47
Orbital Period · P
1.42 yr
v(q)
37.5 km/s
v(Q)
18.8 km/s
Diameter · ≈
0.02 km
TJ
5.04
Eccentricity · e
0.3335

Orbit and dynamics

The path is an ellipse reaching 0.841 AU from the Sun at perihelion and 1.682 AU at aphelion, a radial span of 0.841 AU.

Applying Kepler's third law to a = 1.261 AU gives an orbital period of 1.42 yr, or about 517 days.

An eccentricity of 0.334 makes the orbit moderately elongated.

The orbital plane is tilted 11.38° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 37.5 km/s at perihelion and falls to 18.8 km/s at aphelion.

Because q < 1 AU and Q > 1 AU, this orbit geometrically intersects the region of Earth's orbit.

Size and surface

No direct size measurement is available; from an absolute magnitude of H = 26.3 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.02 km.

Observation record and orbit quality

The current orbit solution is based on 47 observations and has a weighted RMS residual of 0.4088 arcseconds.

Condition code U = 7 signals a poorly constrained orbit, so its future path should be treated as provisional.

About these computed values

Orbital periods, perihelion and aphelion speeds, and diameter estimates on this page are computed by SpaceAtlas from the JPL SBDB orbital elements. They are derived quantities, not values copied from the source catalogue.

Orbital Parameters

Semi-Major Axis
1.261 AU
Eccentricity
0.3335
Perihelion
0.841 AU
Aphelion
1.681543 AU
Inclination
11.38°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
333.05°

Orbit diagram

The Sun sits at the focus (orange). Earth's orbit is the grey circle at 1 AU. The red dot marks the object's position at the catalog epoch.

3D orbit (interactive)

Drag to rotate; scroll or pinch to zoom. The Sun is at the focus (orange), Earth's orbit is the grey ring at 1 AU, and the red dot marks the object's current position.

Close approaches

Predicted close approaches to Earth, from NASA's Center for Near-Earth Object Studies (CNEOS).

Date (UTC)Miss distanceVelocity
2030-Aug-11 16:22 0.116415 AU
17415489 km
9.64 km/s
2045-Jan-27 22:10 0.390013 AU
58345054 km
21.98 km/s
2047-Aug-07 10:59 0.116783 AU
17470549 km
12.79 km/s

Distances in astronomical units (AU) and kilometres. Source: NASA/JPL CNEOS Close Approach Data API.

Physical Parameters

Diameter
— km
Albedo
—
Density
— g/cm³
Rotation Period
— h
Absolute Magnitude
26.3

Orbit Quality

RMS
0.40885
Condition
7
Orbit ID
—
Data source: NASA JPL Small-Body Database · NASA CNEOS. Orbital periods, perihelion and aphelion speeds, and diameter estimates on this page are computed by SpaceAtlas from the JPL SBDB orbital elements. They are derived quantities, not values copied from the source catalogue.

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