SpaceAtlas Space Object Data
NASA JPL SBDB · 2018 HL2

2018 HL2

2018 HL2 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.671 AU it takes 2.16 yr to circle the Sun.

Apollo Observations: 92
Orbital Period · P
2.16 yr
v(q)
38.3 km/s
v(Q)
13.9 km/s
Diameter · ≈
0.2 km
TJ
3.95
Eccentricity · e
0.4679

Orbit and dynamics

Between its closest point (0.889 AU) and its farthest (2.453 AU), the heliocentric distance changes by 1.564 AU over every revolution.

One full revolution takes 2.16 yr (789 days), computed from the semi-major axis of 1.671 AU.

The high eccentricity (0.468) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

A steep inclination of 33.44° carries it well above and below the ecliptic plane.

By the vis-viva equation its orbital speed rises to 38.3 km/s at perihelion and falls to 13.9 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 = 21.3 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.2 km.

Observation record and orbit quality

Astrometry from 92 individual observations underpins this orbit; the fit leaves an RMS residual of 0.4803 arcseconds.

Condition code U = 2 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
1.671 AU
Eccentricity
0.4679
Perihelion
0.889 AU
Aphelion
2.452861 AU
Inclination
33.44°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
246.41°

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-May-01 04:16 0.124744 AU
18661508 km
23.09 km/s
2044-Apr-17 04:10 0.399211 AU
59721081 km
28.69 km/s
2046-Oct-04 23:57 0.491185 AU
73480289 km
19.57 km/s
2059-May-23 12:26 0.286400 AU
42844894 km
18.48 km/s
2072-May-06 00:25 0.013717 AU
2052099 km
21.29 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
21.3

Orbit Quality

RMS
0.48033
Condition
2
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

Explore asteroids, comets and near-Earth objects with JPL orbital data.