SpaceAtlas Space Object Data
NASA JPL SBDB · 4688

4688

4688 is an Amor-type near-Earth asteroid that approaches Earth from beyond our orbit without crossing it, orbiting the Sun at 2.233 AU once every 3.34 yr.

Amor Observations: 332
Orbital Period · P
3.34 yr
v(q)
35.4 km/s
v(Q)
11.2 km/s
Diameter · ≈
0.43 km
TJ
3.44
Eccentricity · e
0.5178

Orbit and dynamics

Between its closest point (1.077 AU) and its farthest (3.389 AU), the heliocentric distance changes by 2.312 AU over every revolution.

One full revolution takes 3.34 yr (1,219 days), computed from the semi-major axis of 2.233 AU.

The high eccentricity (0.518) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

The orbital plane is tilted 6.37° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 35.4 km/s at perihelion and falls to 11.2 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

The measured diameter is 0.6 km, a value from direct size determination rather than from brightness alone.

A geometric albedo of 0.18 points to a comparatively bright, reflective surface.

Observation record and orbit quality

Astrometry from 332 individual observations underpins this orbit; the fit leaves an RMS residual of 0.4379 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
2.233 AU
Eccentricity
0.5178
Perihelion
1.077 AU
Aphelion
3.389247 AU
Inclination
6.37°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
222.5°

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
0.6 km
Albedo
0.18
Density
— g/cm³
Rotation Period
— h
Absolute Magnitude
19.6

Orbit Quality

RMS
0.43788
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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