SpaceAtlas Space Object Data
NASA JPL SBDB · 2021 LL1

2021 LL1

2021 LL1 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.154 AU it takes 1.24 yr to circle the Sun.

Apollo Observations: 31
Orbital Period · P
1.24 yr
v(q)
31.2 km/s
v(Q)
24.6 km/s
Diameter · ≈
0.02 km
TJ
5.42
Eccentricity · e
0.1188

Orbit and dynamics

The path is an ellipse reaching 1.017 AU from the Sun at perihelion and 1.291 AU at aphelion, a radial span of 0.274 AU.

Applying Kepler's third law to a = 1.154 AU gives an orbital period of 1.24 yr, or about 453 days.

An eccentricity of 0.119 makes the orbit moderately elongated.

The orbital plane is tilted 12.05° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 31.2 km/s at perihelion and falls to 24.6 km/s at aphelion.

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

The current orbit solution is based on 31 observations and has a weighted RMS residual of 0.4569 arcseconds.

Condition code U = 7 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
1.154 AU
Eccentricity
0.1188
Perihelion
1.017 AU
Aphelion
1.291095 AU
Inclination
12.05°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
24.86°

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-Apr-20 18:19 0.399881 AU
59821381 km
15.68 km/s
2031-Nov-01 06:09 0.311616 AU
46617038 km
7.28 km/s
2042-Jul-12 16:20 0.357410 AU
53467833 km
16.77 km/s
2067-Oct-09 13:12 0.274324 AU
41038270 km
5.96 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
0.45694
Condition
7
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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