SpaceAtlas Space Object Data
NASA JPL SBDB · 2018 CW2

2018 CW2

2018 CW2 is an Aten-type near-Earth asteroid whose orbit lies mostly inside that of Earth, with a semi-major axis of 0.76 AU and a period of 0.66 yr.

Aten Observations: 161
Orbital Period · P
0.66 yr
v(q)
53.6 km/s
v(Q)
21.8 km/s
Diameter · ≈
0.03 km
TJ
7.54
Eccentricity · e
0.4226

Orbit and dynamics

The path is an ellipse reaching 0.439 AU from the Sun at perihelion and 1.081 AU at aphelion, a radial span of 0.642 AU.

Applying Kepler's third law to a = 0.76 AU gives an orbital period of 0.66 yr, or about 242 days.

The high eccentricity (0.423) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

The orbital plane is tilted 5.1° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 53.6 km/s at perihelion and falls to 21.8 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

No direct size measurement is available; from an absolute magnitude of H = 25.66 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.03 km.

Observation record and orbit quality

The current orbit solution is based on 161 observations and has a weighted RMS residual of 0.3369 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
0.7598 AU
Eccentricity
0.4226
Perihelion
0.439 AU
Aphelion
1.080891 AU
Inclination
5.1°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
60.48°

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
2056-Dec-21 08:25 0.177256 AU
26517060 km
15.57 km/s
2058-Dec-20 20:22 0.119809 AU
17923127 km
13.26 km/s
2060-Dec-21 02:28 0.082586 AU
12354740 km
11.18 km/s
2062-Dec-25 16:17 0.080151 AU
11990476 km
9.61 km/s
2065-Jan-02 16:18 0.097458 AU
14579572 km
8.87 km/s
2067-Jan-14 02:57 0.109069 AU
16316512 km
8.74 km/s
2069-Jan-24 19:51 0.105809 AU
15828833 km
8.73 km/s
2071-Feb-05 02:06 0.085954 AU
12858505 km
8.81 km/s
2073-Feb-13 03:21 0.050876 AU
7610894 km
9.31 km/s
2075-Feb-18 05:17 0.007877 AU
1178432 km
10.43 km/s
2077-Feb-18 11:48 0.008125 AU
1215516 km
10.88 km/s
2079-Feb-20 02:21 0.063309 AU
9470940 km
12.62 km/s

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

Physical Parameters

Diameter
— km
Albedo
—
Density
— g/cm³
Rotation Period
— h
Absolute Magnitude
25.66

Orbit Quality

RMS
0.33688
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.

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