SpaceAtlas Space Object Data
NASA JPL SBDB · 499998

499998

499998 is an Amor-type near-Earth asteroid that approaches Earth from beyond our orbit without crossing it, orbiting the Sun at 1.316 AU once every 1.51 yr.

Amor Observations: 205
Orbital Period · P
1.51 yr
v(q)
32.4 km/s
v(Q)
20.8 km/s
Diameter · ≈
0.06 km
TJ
4.94
Eccentricity · e
0.2166

Orbit and dynamics

Between its closest point (1.031 AU) and its farthest (1.601 AU), the heliocentric distance changes by 0.57 AU over every revolution.

One full revolution takes 1.51 yr (551 days), computed from the semi-major axis of 1.316 AU.

An eccentricity of 0.217 makes the orbit moderately elongated.

Its inclination of 2.22° keeps it close to the plane of the ecliptic.

By the vis-viva equation its orbital speed rises to 32.4 km/s at perihelion and falls to 20.8 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 = 24.01 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.06 km.

Observation record and orbit quality

Astrometry from 205 individual observations underpins this orbit; the fit leaves an RMS residual of 0.5129 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
1.316 AU
Eccentricity
0.2166
Perihelion
1.031 AU
Aphelion
1.601046 AU
Inclination
2.22°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
270.18°

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
24.01

Orbit Quality

RMS
0.51285
Condition
0
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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