SpaceAtlas Space Object Data
NASA JPL SBDB · 2018 AD4

2018 AD4

2018 AD4 is an Aten-type near-Earth asteroid whose orbit lies mostly inside that of Earth, with a semi-major axis of 0.929 AU and a period of 0.90 yr.

Aten Observations: 83
Orbital Period · P
0.90 yr
v(q)
38.6 km/s
v(Q)
24.7 km/s
Diameter · ≈
0.1 km
TJ
6.4
Eccentricity · e
0.2187

Orbit and dynamics

Between its closest point (0.726 AU) and its farthest (1.132 AU), the heliocentric distance changes by 0.406 AU over every revolution.

One full revolution takes 0.90 yr (327 days), computed from the semi-major axis of 0.929 AU.

An eccentricity of 0.219 makes the orbit moderately elongated.

The orbital plane is tilted 13.57° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 38.6 km/s at perihelion and falls to 24.7 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 = 22.72 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.1 km.

Observation record and orbit quality

Astrometry from 83 individual observations underpins this orbit; the fit leaves an RMS residual of 0.4585 arcseconds.

Condition code U = 1 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
0.9289 AU
Eccentricity
0.2187
Perihelion
0.726 AU
Aphelion
1.13205 AU
Inclination
13.57°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
293.38°

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

No close approaches to Earth are currently on record for this object.

Physical Parameters

Diameter
— km
Albedo
—
Density
— g/cm³
Rotation Period
— h
Absolute Magnitude
22.72

Orbit Quality

RMS
0.45851
Condition
1
Orbit ID
—
Data source: NASA JPL Small-Body Database . 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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