SpaceAtlas Space Object Data
NASA JPL SBDB · 2010 GU21

2010 GU21

2010 GU21 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 2.18 AU it takes 3.22 yr to circle the Sun.

Apollo Observations: 458
Orbital Period · P
3.22 yr
v(q)
38.2 km/s
v(Q)
10.7 km/s
Diameter · ≈
0.21 km
TJ
3.45
Eccentricity · e
0.5639

Orbit and dynamics

The path is an ellipse reaching 0.951 AU from the Sun at perihelion and 3.409 AU at aphelion, a radial span of 2.458 AU.

Applying Kepler's third law to a = 2.18 AU gives an orbital period of 3.22 yr, or about 1,176 days.

The high eccentricity (0.564) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

Its inclination of 3.16° keeps it close to the plane of the ecliptic.

By the vis-viva equation its orbital speed rises to 38.2 km/s at perihelion and falls to 10.7 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

The measured diameter is 0.51 km, a value from direct size determination rather than from brightness alone.

Its geometric albedo of 0.025 indicates a very dark, carbonaceous-type surface.

Observation record and orbit quality

The current orbit solution is based on 458 observations and has a weighted RMS residual of 0.3015 arcseconds.

Condition code U = 0 means the orbit is very well determined, leaving only a small uncertainty in the future ephemeris.

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
2.18 AU
Eccentricity
0.5639
Perihelion
0.951 AU
Aphelion
3.409302 AU
Inclination
3.16°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
350.53°

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
2039-Apr-24 07:53 0.107876 AU
16137988 km
13.36 km/s
2055-Aug-04 03:46 0.171471 AU
25651723 km
15.18 km/s

Distances in astronomical units (AU) and kilometres. Source: NASA/JPL CNEOS Close Approach Data API.

Physical Parameters

Diameter
0.51 km
Albedo
0.025
Density
— g/cm³
Rotation Period
— h
Absolute Magnitude
21.14

Orbit Quality

RMS
0.30148
Condition
0
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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