SpaceAtlas Space Object Data
NASA JPL SBDB · 2021 WH3

2021 WH3

2021 WH3 is an Aten-type near-Earth asteroid whose orbit lies mostly inside that of Earth, with a semi-major axis of 0.879 AU and a period of 0.82 yr.

Aten Observations: 41
Orbital Period · P
0.82 yr
v(q)
43.4 km/s
v(Q)
23.3 km/s
Diameter · ≈
0.02 km
TJ
6.7
Eccentricity · e
0.3014

Orbit and dynamics

Between its closest point (0.614 AU) and its farthest (1.144 AU), the heliocentric distance changes by 0.53 AU over every revolution.

One full revolution takes 0.82 yr (301 days), computed from the semi-major axis of 0.879 AU.

An eccentricity of 0.301 makes the orbit moderately elongated.

Its inclination of 4.68° keeps it close to the plane of the ecliptic.

By the vis-viva equation its orbital speed rises to 43.4 km/s at perihelion and falls to 23.3 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 = 25.9 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.02 km.

Observation record and orbit quality

Astrometry from 41 individual observations underpins this orbit; the fit leaves an RMS residual of 0.4095 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
0.8789 AU
Eccentricity
0.3014
Perihelion
0.614 AU
Aphelion
1.1438 AU
Inclination
4.68°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
280.19°

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
2027-Jan-18 16:10 0.175131 AU
26199186 km
7.07 km/s
2027-Apr-27 15:33 0.276170 AU
41314427 km
7.15 km/s
2030-Dec-06 04:03 0.382062 AU
57155702 km
21.50 km/s
2031-Aug-04 04:29 0.395790 AU
59209388 km
13.57 km/s
2032-Mar-04 20:18 0.089983 AU
13461328 km
10.71 km/s
2035-Nov-25 06:21 0.041686 AU
6236192 km
10.96 km/s
2036-Jun-24 23:51 0.393708 AU
58897888 km
13.62 km/s
2037-Feb-21 15:27 0.378509 AU
56624157 km
21.16 km/s
2040-Oct-10 08:18 0.250910 AU
37535619 km
5.25 km/s
2040-Dec-31 18:14 0.161767 AU
24199935 km
7.07 km/s
2041-May-14 10:51 0.314304 AU
47019277 km
9.54 km/s
2045-Aug-18 11:44 0.376634 AU
56343588 km
12.41 km/s
2046-Mar-03 14:39 0.088372 AU
13220226 km
7.19 km/s
2049-Nov-29 00:27 0.197528 AU
29549814 km
15.78 km/s
2050-Jul-14 03:03 0.404539 AU
60518100 km
14.13 km/s
2051-Feb-28 12:46 0.229041 AU
34264071 km
16.13 km/s
2054-Nov-28 18:27 0.055578 AU
8314368 km
7.22 km/s
2055-Jun-08 15:06 0.370570 AU
55436527 km
12.38 km/s
2059-Sep-11 00:35 0.333421 AU
49879125 km
9.72 km/s
2060-Jan-28 19:04 0.170073 AU
25442554 km
6.94 km/s
2060-Apr-12 18:22 0.243498 AU
36426787 km
5.09 km/s
2063-Dec-04 19:59 0.348776 AU
52176162 km
20.04 km/s
2064-Jul-28 19:30 0.401576 AU
60074952 km
13.85 km/s
2065-Mar-03 23:52 0.133411 AU
19958042 km
12.30 km/s
2068-Nov-24 05:34 0.009766 AU
1461034 km
9.41 km/s
2069-Jun-20 07:13 0.386138 AU
57765382 km
13.23 km/s
2070-Feb-21 03:47 0.425386 AU
63636838 km
22.25 km/s
2073-Dec-27 12:38 0.158791 AU
23754776 km
6.99 km/s
2074-May-19 15:18 0.328826 AU
49191669 km
10.06 km/s
2078-Aug-31 07:20 0.351395 AU
52567951 km
11.05 km/s
2079-Feb-12 13:29 0.142802 AU
21362830 km
6.56 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
25.9

Orbit Quality

RMS
0.40951
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.

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