SpaceAtlas Space Object Data
NASA JPL SBDB · 2021 PW2

2021 PW2

2021 PW2 is an Aten-type near-Earth asteroid whose orbit lies mostly inside that of Earth, with a semi-major axis of 0.856 AU and a period of 0.79 yr.

Aten Observations: 18
Orbital Period · P
0.79 yr
v(q)
42.6 km/s
v(Q)
24.4 km/s
Diameter · ≈
0.03 km
TJ
6.86
Eccentricity · e
0.2721

Orbit and dynamics

The path is an ellipse reaching 0.623 AU from the Sun at perihelion and 1.088 AU at aphelion, a radial span of 0.465 AU.

Applying Kepler's third law to a = 0.856 AU gives an orbital period of 0.79 yr, or about 289 days.

An eccentricity of 0.272 makes the orbit moderately elongated.

The orbital plane is tilted 5.52° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 42.6 km/s at perihelion and falls to 24.4 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 = 25.68 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.03 km.

Observation record and orbit quality

The current orbit solution is based on 18 observations and has a weighted RMS residual of 0.4162 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
0.8555 AU
Eccentricity
0.2721
Perihelion
0.623 AU
Aphelion
1.088282 AU
Inclination
5.52°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
252.38°

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-Jun-23 00:19 0.405677 AU
60688474 km
19.93 km/s
2029-Jan-17 00:06 0.360341 AU
53906247 km
12.75 km/s
2029-Aug-16 04:15 0.441035 AU
65977913 km
21.33 km/s
2032-Jun-13 23:29 0.132666 AU
19846599 km
12.08 km/s
2078-Aug-28 09:16 0.046345 AU
6933088 km
9.72 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
25.68

Orbit Quality

RMS
0.41617
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.

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