SpaceAtlas Space Object Data
NASA JPL SBDB · 198856

198856

198856 is an Amor-type near-Earth asteroid that approaches Earth from beyond our orbit without crossing it, orbiting the Sun at 1.654 AU once every 2.13 yr.

Amor Observations: 1,391
Orbital Period · P
2.13 yr
v(q)
32.8 km/s
v(Q)
16.3 km/s
Diameter · ≈
1.37 km
TJ
4.11
Eccentricity · e
0.3353

Orbit and dynamics

Between its closest point (1.099 AU) and its farthest (2.209 AU), the heliocentric distance changes by 1.11 AU over every revolution.

One full revolution takes 2.13 yr (777 days), computed from the semi-major axis of 1.654 AU.

An eccentricity of 0.335 makes the orbit moderately elongated.

A steep inclination of 25° carries it well above and below the ecliptic plane.

By the vis-viva equation its orbital speed rises to 32.8 km/s at perihelion and falls to 16.3 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 0.74 km, a value from direct size determination rather than from brightness alone.

A geometric albedo of 0.389 points to a comparatively bright, reflective surface.

Observation record and orbit quality

Astrometry from 1,391 individual observations underpins this orbit; the fit leaves an RMS residual of 0.4681 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
1.654 AU
Eccentricity
0.3353
Perihelion
1.099 AU
Aphelion
2.208586 AU
Inclination
25.0°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
83.26°

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
2076-Dec-07 18:36 0.166851 AU
24960606 km
14.61 km/s

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

Physical Parameters

Diameter
0.742 km
Albedo
0.389
Density
— g/cm³
Rotation Period
— h
Absolute Magnitude
17.07

Orbit Quality

RMS
0.46812
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.