SpaceAtlas Space Object Data
NASA JPL SBDB · 2021 DX

2021 DX

2021 DX belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.243 AU it takes 1.39 yr to circle the Sun.

Apollo Observations: 42
Orbital Period · P
1.39 yr
v(q)
32.2 km/s
v(Q)
22.2 km/s
Diameter · ≈
0.04 km
TJ
5.14
Eccentricity · e
0.1842

Orbit and dynamics

Between its closest point (1.014 AU) and its farthest (1.472 AU), the heliocentric distance changes by 0.458 AU over every revolution.

One full revolution takes 1.39 yr (506 days), computed from the semi-major axis of 1.243 AU.

An eccentricity of 0.184 makes the orbit moderately elongated.

The orbital plane is tilted 8.47° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 32.2 km/s at perihelion and falls to 22.2 km/s at aphelion.

Size and surface

No direct size measurement is available; from an absolute magnitude of H = 24.51 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.04 km.

Observation record and orbit quality

Astrometry from 42 individual observations underpins this orbit; the fit leaves an RMS residual of 0.3376 arcseconds.

Condition code U = 5 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
1.243 AU
Eccentricity
0.1842
Perihelion
1.014 AU
Aphelion
1.471961 AU
Inclination
8.47°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
235.29°

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
2028-Mar-20 09:37 0.331178 AU
49543595 km
13.81 km/s
2028-Sep-05 00:59 0.326360 AU
48822749 km
6.29 km/s
2032-Jan-02 18:17 0.438548 AU
65605886 km
6.66 km/s
2035-Oct-16 14:19 0.461480 AU
69036361 km
7.97 km/s
2039-Mar-19 12:45 0.196430 AU
29385494 km
4.41 km/s
2039-Jun-30 19:47 0.184153 AU
27548898 km
6.66 km/s
2046-Mar-24 00:39 0.245123 AU
36669911 km
11.65 km/s
2046-Aug-27 15:21 0.289517 AU
43311084 km
5.77 km/s
2049-Dec-24 22:41 0.459172 AU
68691193 km
7.06 km/s
2053-Oct-08 22:01 0.440440 AU
65888943 km
7.80 km/s
2057-Feb-20 11:39 0.273395 AU
40899367 km
4.67 km/s
2057-Jul-07 12:54 0.249025 AU
37253545 km
9.62 km/s
2064-Mar-27 17:01 0.142417 AU
21305302 km
8.82 km/s
2064-Aug-12 16:04 0.239340 AU
35804741 km
4.88 km/s
2067-Dec-16 12:21 0.479266 AU
71697184 km
7.40 km/s
2071-Oct-01 12:42 0.416109 AU
62249043 km
7.52 km/s
2075-Feb-04 19:42 0.332169 AU
49691791 km
5.18 km/s
2075-Jul-13 02:25 0.329902 AU
49352705 km
12.21 km/s
2078-Nov-05 16:32 0.498481 AU
74571683 km
8.22 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
24.51

Orbit Quality

RMS
0.33756
Condition
5
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

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