SpaceAtlas Space Object Data
NASA JPL SBDB · 2023 RP21

2023 RP21

2023 RP21 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.647 AU it takes 2.11 yr to circle the Sun.

Apollo Observations: 46
Orbital Period · P
2.11 yr
v(q)
35.5 km/s
v(Q)
15.2 km/s
Diameter · ≈
0.1 km
TJ
4.06
Eccentricity · e
0.4019

Orbit and dynamics

Between its closest point (0.985 AU) and its farthest (2.309 AU), the heliocentric distance changes by 1.324 AU over every revolution.

One full revolution takes 2.11 yr (772 days), computed from the semi-major axis of 1.647 AU.

The high eccentricity (0.402) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

A steep inclination of 29.32° carries it well above and below the ecliptic plane.

By the vis-viva equation its orbital speed rises to 35.5 km/s at perihelion and falls to 15.2 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 = 22.65 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.1 km.

Observation record and orbit quality

Astrometry from 46 individual observations underpins this orbit; the fit leaves an RMS residual of 0.6273 arcseconds.

Condition code U = 6 indicates a moderately constrained orbit; predictions decades ahead still carry noticeable uncertainty.

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
1.647 AU
Eccentricity
0.4019
Perihelion
0.985 AU
Aphelion
2.308929 AU
Inclination
29.32°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
67.95°

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
2042-Oct-12 22:12 0.206179 AU
30843874 km
15.40 km/s
2043-Feb-26 05:32 0.422960 AU
63273841 km
16.49 km/s
2059-Oct-01 00:24 0.246238 AU
36836698 km
23.06 km/s
2061-Oct-11 20:03 0.312092 AU
46688273 km
14.76 km/s
2062-Feb-25 20:36 0.431982 AU
64623551 km
19.16 km/s
2078-Oct-06 14:22 0.172408 AU
25791894 km
19.48 km/s
2079-Mar-05 08:39 0.443669 AU
66371868 km
14.81 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
22.65

Orbit Quality

RMS
0.62735
Condition
6
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.

Keep exploring

Explore asteroids, comets and near-Earth objects with JPL orbital data.