SpaceAtlas Space Object Data
NASA JPL SBDB · 2021 TM

2021 TM

2021 TM belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.871 AU it takes 2.56 yr to circle the Sun.

Apollo Observations: 43
Orbital Period · P
2.56 yr
v(q)
41.4 km/s
v(Q)
11.5 km/s
Diameter · ≈
0.01 km
TJ
3.76
Eccentricity · e
0.5664

Orbit and dynamics

Between its closest point (0.811 AU) and its farthest (2.931 AU), the heliocentric distance changes by 2.12 AU over every revolution.

One full revolution takes 2.56 yr (935 days), computed from the semi-major axis of 1.871 AU.

The high eccentricity (0.566) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

The orbital plane is tilted 8.91° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 41.4 km/s at perihelion and falls to 11.5 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 = 27.39 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.01 km.

Observation record and orbit quality

Astrometry from 43 individual observations underpins this orbit; the fit leaves an RMS residual of 0.2717 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
1.871 AU
Eccentricity
0.5664
Perihelion
0.811 AU
Aphelion
2.930734 AU
Inclination
8.91°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
281.46°

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-Feb-12 05:22 0.135264 AU
20235190 km
16.03 km/s
2050-Feb-23 01:43 0.156274 AU
23378219 km
21.70 km/s
2073-Mar-04 22:57 0.293816 AU
43954281 km
27.47 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
27.39

Orbit Quality

RMS
0.27171
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

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