SpaceAtlas Space Object Data
NASA JPL SBDB · 1998 WB2

1998 WB2

1998 WB2 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.972 AU it takes 2.77 yr to circle the Sun.

Apollo Observations: 320
Orbital Period · P
2.77 yr
v(q)
41.6 km/s
v(Q)
10.8 km/s
Diameter · ≈
0.15 km
TJ
3.64
Eccentricity · e
0.5867

Orbit and dynamics

Between its closest point (0.815 AU) and its farthest (3.129 AU), the heliocentric distance changes by 2.314 AU over every revolution.

One full revolution takes 2.77 yr (1,011 days), computed from the semi-major axis of 1.972 AU.

The high eccentricity (0.587) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

Its inclination of 2.37° keeps it close to the plane of the ecliptic.

By the vis-viva equation its orbital speed rises to 41.6 km/s at perihelion and falls to 10.8 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 0.15 km, a value from direct size determination rather than from brightness alone.

A geometric albedo of 0.151 points to a comparatively bright, reflective surface.

Observation record and orbit quality

Astrometry from 320 individual observations underpins this orbit; the fit leaves an RMS residual of 0.3969 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
1.972 AU
Eccentricity
0.5867
Perihelion
0.815 AU
Aphelion
3.128972 AU
Inclination
2.37°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
312.43°

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
0.15 km
Albedo
0.151
Density
— g/cm³
Rotation Period
— h
Absolute Magnitude
21.85

Orbit Quality

RMS
0.39689
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.

Keep exploring

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