SpaceAtlas Space Object Data
NASA JPL SBDB · 2026 HM4

2026 HM4

2026 HM4 is an Aten-type near-Earth asteroid whose orbit lies mostly inside that of Earth, with a semi-major axis of 0.972 AU and a period of 0.96 yr.

Aten Observations: 58
Orbital Period · P
0.96 yr
v(q)
46.9 km/s
v(Q)
19.5 km/s
Diameter · ≈
0.08 km
TJ
6.08
Eccentricity · e
0.4133

Orbit and dynamics

The path is an ellipse reaching 0.57 AU from the Sun at perihelion and 1.373 AU at aphelion, a radial span of 0.803 AU.

Applying Kepler's third law to a = 0.972 AU gives an orbital period of 0.96 yr, or about 350 days.

The high eccentricity (0.413) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

A steep inclination of 22.83° carries it well above and below the ecliptic plane.

By the vis-viva equation its orbital speed rises to 46.9 km/s at perihelion and falls to 19.5 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 = 23.17 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.08 km.

Observation record and orbit quality

The current orbit solution is based on 58 observations and has a weighted RMS residual of 0.5346 arcseconds.

Condition code U = 6 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
0.9718 AU
Eccentricity
0.4133
Perihelion
0.57 AU
Aphelion
1.373445 AU
Inclination
22.83°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
303.1°

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
2027-May-07 15:11 0.099424 AU
14873690 km
18.17 km/s
2049-May-08 16:27 0.083629 AU
12510666 km
14.51 km/s
2050-May-05 20:50 0.105474 AU
15778621 km
19.75 km/s
2072-May-08 17:58 0.069771 AU
10437605 km
15.50 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
23.17

Orbit Quality

RMS
0.53462
Condition
6
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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