SpaceAtlas Space Object Data
NASA JPL SBDB · 2018 HR3

2018 HR3

2018 HR3 is an Amor-type near-Earth asteroid that approaches Earth from beyond our orbit without crossing it, orbiting the Sun at 2.698 AU once every 4.43 yr.

Amor Observations: 100
Orbital Period · P
4.43 yr
v(q)
32.9 km/s
v(Q)
10 km/s
Diameter · ≈
0.55 km
TJ
3.08
Eccentricity · e
0.5344

Orbit and dynamics

The path is an ellipse reaching 1.256 AU from the Sun at perihelion and 4.14 AU at aphelion, a radial span of 2.884 AU.

Applying Kepler's third law to a = 2.698 AU gives an orbital period of 4.43 yr, or about 1,619 days.

The high eccentricity (0.534) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

The orbital plane is tilted 18.9° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 32.9 km/s at perihelion and falls to 10 km/s at aphelion.

Its perihelion lies just outside Earth's orbit, which is why it is classed as Earth-approaching rather than Earth-crossing.

Size and surface

No direct size measurement is available; from an absolute magnitude of H = 19.04 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.55 km.

Observation record and orbit quality

The current orbit solution is based on 100 observations and has a weighted RMS residual of 0.5883 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
2.698 AU
Eccentricity
0.5344
Perihelion
1.256 AU
Aphelion
4.139811 AU
Inclination
18.9°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
340.58°

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-Dec-29 03:36 0.473691 AU
70863226 km
8.95 km/s
2079-Dec-23 23:37 0.430851 AU
64454390 km
8.62 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
19.04

Orbit Quality

RMS
0.58825
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.

Keep exploring

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