SpaceAtlas Space Object Data
NASA JPL SBDB · 2012 HJ8

2012 HJ8

2012 HJ8 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.917 AU it takes 2.65 yr to circle the Sun.

Apollo Observations: 43
Orbital Period · P
2.65 yr
v(q)
53.4 km/s
v(Q)
8.7 km/s
Diameter · ≈
0.22 km
TJ
3.53
Eccentricity · e
0.7211

Orbit and dynamics

The path is an ellipse reaching 0.535 AU from the Sun at perihelion and 3.299 AU at aphelion, a radial span of 2.764 AU.

Applying Kepler's third law to a = 1.917 AU gives an orbital period of 2.65 yr, or about 969 days.

The high eccentricity (0.721) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

The orbital plane is tilted 13.72° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 53.4 km/s at perihelion and falls to 8.7 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 = 21 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.22 km.

Observation record and orbit quality

The current orbit solution is based on 43 observations and has a weighted RMS residual of 0.5022 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
1.917 AU
Eccentricity
0.7211
Perihelion
0.535 AU
Aphelion
3.299349 AU
Inclination
13.72°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
141.77°

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-Jan-30 04:37 0.416360 AU
62286559 km
22.62 km/s
2036-Jan-06 10:59 0.451672 AU
67569165 km
24.72 km/s
2043-Dec-11 11:58 0.452479 AU
67689851 km
23.23 km/s
2051-Nov-08 20:45 0.390373 AU
58399010 km
16.79 km/s
2059-Oct-04 13:21 0.248385 AU
37157848 km
17.89 km/s
2065-Apr-24 15:41 0.448468 AU
67089833 km
33.50 km/s
2067-Sep-20 22:08 0.228137 AU
34128786 km
24.99 km/s
2073-Apr-10 16:02 0.260756 AU
39008570 km
25.96 km/s
2075-Sep-08 07:52 0.412281 AU
61676422 km
32.69 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
21.0

Orbit Quality

RMS
0.50225
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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