SpaceAtlas Space Object Data
NASA JPL SBDB · 2021 JB

2021 JB

2021 JB is an Aten-type near-Earth asteroid whose orbit lies mostly inside that of Earth, with a semi-major axis of 0.931 AU and a period of 0.90 yr.

Aten Observations: 41
Orbital Period · P
0.90 yr
v(q)
41.5 km/s
v(Q)
23 km/s
Diameter · ≈
0.02 km
TJ
6.39
Eccentricity · e
0.2874

Orbit and dynamics

Between its closest point (0.663 AU) and its farthest (1.199 AU), the heliocentric distance changes by 0.536 AU over every revolution.

One full revolution takes 0.90 yr (328 days), computed from the semi-major axis of 0.931 AU.

An eccentricity of 0.287 makes the orbit moderately elongated.

The orbital plane is tilted 6.68° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 41.5 km/s at perihelion and falls to 23 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 = 26.69 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 0.3921 arcseconds.

Condition code U = 4 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
0.931 AU
Eccentricity
0.2874
Perihelion
0.663 AU
Aphelion
1.198569 AU
Inclination
6.68°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
342.2°

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
2029-May-15 07:45 0.493984 AU
73898882 km
23.08 km/s
2030-May-07 02:14 0.106145 AU
15879109 km
6.25 km/s
2030-Dec-13 22:11 0.322247 AU
48207482 km
11.44 km/s
2031-Aug-29 09:22 0.116583 AU
17440634 km
9.34 km/s
2038-May-09 19:11 0.357399 AU
53466180 km
18.94 km/s
2039-Feb-28 17:19 0.259440 AU
38811741 km
6.55 km/s
2039-Jun-06 19:46 0.187426 AU
28038460 km
6.54 km/s
2039-Nov-22 11:25 0.298279 AU
44621864 km
10.41 km/s
2040-Aug-21 15:41 0.225209 AU
33690778 km
13.90 km/s
2047-May-03 02:15 0.185541 AU
27756530 km
13.82 km/s
2048-Jan-26 17:34 0.313722 AU
46932079 km
10.06 km/s
2048-Jul-10 09:12 0.205768 AU
30782483 km
6.38 km/s
2048-Oct-22 12:13 0.241642 AU
36149112 km
7.80 km/s
2049-Aug-13 20:20 0.384040 AU
57451534 km
19.08 km/s
2056-Apr-28 00:15 0.016116 AU
2410879 km
8.81 km/s
2057-Jan-01 20:27 0.327372 AU
48974191 km
11.32 km/s
2057-Sep-03 13:56 0.141283 AU
21135669 km
5.43 km/s
2065-Apr-29 05:40 0.034672 AU
5186817 km
7.24 km/s
2065-Dec-24 04:36 0.326039 AU
48774799 km
11.47 km/s
2066-Sep-02 04:02 0.108928 AU
16295413 km
7.19 km/s
2073-May-14 08:29 0.458027 AU
68519904 km
22.05 km/s
2074-May-14 15:11 0.131807 AU
19718087 km
6.14 km/s
2074-Dec-09 03:04 0.317029 AU
47426911 km
11.24 km/s
2075-Aug-28 07:10 0.134840 AU
20171752 km
10.48 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
26.69

Orbit Quality

RMS
0.39213
Condition
4
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.