SpaceAtlas Space Object Data
NASA JPL SBDB · 2018 SY2

2018 SY2

2018 SY2 is an Aten-type near-Earth asteroid whose orbit lies mostly inside that of Earth, with a semi-major axis of 0.774 AU and a period of 0.68 yr.

Aten Observations: 35
Orbital Period · P
0.68 yr
v(q)
50.7 km/s
v(Q)
22.6 km/s
Diameter · ≈
0.25 km
TJ
7.36
Eccentricity · e
0.3839

Orbit and dynamics

The path is an ellipse reaching 0.477 AU from the Sun at perihelion and 1.071 AU at aphelion, a radial span of 0.594 AU.

Applying Kepler's third law to a = 0.774 AU gives an orbital period of 0.68 yr, or about 249 days.

An eccentricity of 0.384 makes the orbit moderately elongated.

A steep inclination of 26.77° carries it well above and below the ecliptic plane.

By the vis-viva equation its orbital speed rises to 50.7 km/s at perihelion and falls to 22.6 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

No direct size measurement is available; from an absolute magnitude of H = 20.8 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.25 km.

Observation record and orbit quality

The current orbit solution is based on 35 observations and has a weighted RMS residual of 0.6226 arcseconds.

Condition code U = 3 indicates a moderately constrained orbit; predictions decades ahead still carry noticeable uncertainty.

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
0.7736 AU
Eccentricity
0.3839
Perihelion
0.477 AU
Aphelion
1.070585 AU
Inclination
26.77°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
315.08°

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
20.8

Orbit Quality

RMS
0.62257
Condition
3
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.