SpaceAtlas Space Object Data
NASA JPL SBDB · 85818

85818

85818 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.657 AU it takes 2.13 yr to circle the Sun.

Apollo Observations: 1,751
Orbital Period · P
2.13 yr
v(q)
36 km/s
v(Q)
14.9 km/s
Diameter · ≈
2.93 km
TJ
3.61
Eccentricity · e
0.4161

Orbit and dynamics

Between its closest point (0.967 AU) and its farthest (2.346 AU), the heliocentric distance changes by 1.379 AU over every revolution.

One full revolution takes 2.13 yr (779 days), computed from the semi-major axis of 1.657 AU.

The high eccentricity (0.416) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

A steep inclination of 62.72° carries it well above and below the ecliptic plane.

By the vis-viva equation its orbital speed rises to 36 km/s at perihelion and falls to 14.9 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

The measured diameter is 2.03 km, a value from direct size determination rather than from brightness alone.

A geometric albedo of 0.168 points to a comparatively bright, reflective surface.

Observation record and orbit quality

Astrometry from 1,751 individual observations underpins this orbit; the fit leaves an RMS residual of 0.4614 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
1.657 AU
Eccentricity
0.4161
Perihelion
0.967 AU
Aphelion
2.346478 AU
Inclination
62.72°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
223.86°

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-18 07:26 0.126005 AU
18850049 km
33.29 km/s
2059-May-15 20:38 0.113353 AU
16957375 km
32.62 km/s

Distances in astronomical units (AU) and kilometres. Source: NASA/JPL CNEOS Close Approach Data API.

Physical Parameters

Diameter
2.028 km
Albedo
0.168
Density
— g/cm³
Rotation Period
— h
Absolute Magnitude
15.42

Orbit Quality

RMS
0.46144
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

Explore asteroids, comets and near-Earth objects with JPL orbital data.