SpaceAtlas Space Object Data
NASA JPL SBDB · 2017 HJ1

2017 HJ1

2017 HJ1 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 2.124 AU it takes 3.10 yr to circle the Sun.

Apollo Observations: 51
Orbital Period · P
3.10 yr
v(q)
37.2 km/s
v(Q)
11.2 km/s
Diameter · ≈
0.17 km
TJ
3.47
Eccentricity · e
0.5357

Orbit and dynamics

The path is an ellipse reaching 0.986 AU from the Sun at perihelion and 3.262 AU at aphelion, a radial span of 2.276 AU.

Applying Kepler's third law to a = 2.124 AU gives an orbital period of 3.10 yr, or about 1,131 days.

The high eccentricity (0.536) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

The orbital plane is tilted 19.32° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 37.2 km/s at perihelion and falls to 11.2 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 = 21.6 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.17 km.

Observation record and orbit quality

The current orbit solution is based on 51 observations and has a weighted RMS residual of 0.4887 arcseconds.

Condition code U = 5 indicates a moderately constrained orbit; predictions decades ahead still carry noticeable uncertainty.

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
2.124 AU
Eccentricity
0.5357
Perihelion
0.986 AU
Aphelion
3.261827 AU
Inclination
19.32°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
316.49°

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
2048-May-11 20:37 0.223306 AU
33406053 km
12.66 km/s
2048-Aug-24 22:34 0.370025 AU
55354928 km
8.55 km/s
2051-Sep-15 11:23 0.457197 AU
68395628 km
23.13 km/s
2079-May-13 18:23 0.225874 AU
33790254 km
12.07 km/s
2079-Aug-25 15:23 0.330281 AU
49409285 km
8.97 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
21.6

Orbit Quality

RMS
0.48873
Condition
5
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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