SpaceAtlas Space Object Data
NASA JPL SBDB · 2021 XD2

2021 XD2

2021 XD2 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.184 AU it takes 1.29 yr to circle the Sun.

Apollo Observations: 49
Orbital Period · P
1.29 yr
v(q)
35 km/s
v(Q)
21.4 km/s
Diameter · ≈
0.01 km
TJ
5.31
Eccentricity · e
0.2421

Orbit and dynamics

The path is an ellipse reaching 0.898 AU from the Sun at perihelion and 1.471 AU at aphelion, a radial span of 0.573 AU.

Applying Kepler's third law to a = 1.184 AU gives an orbital period of 1.29 yr, or about 471 days.

An eccentricity of 0.242 makes the orbit moderately elongated.

The orbital plane is tilted 7.15° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 35 km/s at perihelion and falls to 21.4 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 = 27.3 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.01 km.

Observation record and orbit quality

The current orbit solution is based on 49 observations and has a weighted RMS residual of 0.6109 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
1.184 AU
Eccentricity
0.2421
Perihelion
0.898 AU
Aphelion
1.470646 AU
Inclination
7.15°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
137.42°

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
2031-May-10 03:36 0.191125 AU
28591897 km
4.56 km/s
2035-Aug-05 07:13 0.473044 AU
70766379 km
8.16 km/s
2039-Oct-27 17:03 0.279777 AU
41853972 km
4.95 km/s
2040-Apr-18 14:07 0.098276 AU
14701912 km
5.82 km/s
2044-Jul-22 07:43 0.450177 AU
67345451 km
8.04 km/s
2048-Oct-02 06:42 0.359059 AU
53714450 km
6.41 km/s
2049-Apr-26 17:27 0.119744 AU
17913456 km
10.60 km/s
2052-Nov-20 18:55 0.249205 AU
37280495 km
16.35 km/s
2053-Jul-07 08:33 0.400725 AU
59947546 km
7.64 km/s
2057-Sep-13 01:20 0.421494 AU
63054561 km
7.35 km/s
2058-May-05 20:46 0.260265 AU
38935069 km
16.06 km/s
2061-Dec-01 02:59 0.042079 AU
6294916 km
10.85 km/s
2066-Aug-28 22:00 0.459530 AU
68744678 km
7.86 km/s
2071-May-31 03:53 0.242368 AU
36257710 km
5.82 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
27.3

Orbit Quality

RMS
0.61088
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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