SpaceAtlas Space Object Data
NASA JPL SBDB · 2021 BL2

2021 BL2

2021 BL2 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.257 AU it takes 1.41 yr to circle the Sun.

Apollo Observations: 9
Orbital Period · P
1.41 yr
v(q)
42.3 km/s
v(Q)
16.7 km/s
Diameter · ≈
0.01 km
TJ
5.03
Eccentricity · e
0.4336

Orbit and dynamics

The path is an ellipse reaching 0.712 AU from the Sun at perihelion and 1.802 AU at aphelion, a radial span of 1.09 AU.

Applying Kepler's third law to a = 1.257 AU gives an orbital period of 1.41 yr, or about 515 days.

The high eccentricity (0.434) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

Its inclination of 1.84° keeps it close to the plane of the ecliptic.

By the vis-viva equation its orbital speed rises to 42.3 km/s at perihelion and falls to 16.7 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 = 28.56 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 9 observations and has a weighted RMS residual of 0.4028 arcseconds.

Condition code U = 8 signals a poorly constrained orbit, so its future path should be treated as provisional.

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
1.257 AU
Eccentricity
0.4336
Perihelion
0.712 AU
Aphelion
1.802035 AU
Inclination
1.84°
Orbital Period
— yr
Epoch
2459232.5
Mean Anomaly
42.02°

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
2054-Jun-29 14:16 0.347221 AU
51943458 km
25.30 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
28.56

Orbit Quality

RMS
0.40284
Condition
8
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.