2003 CL18
2003 CL18 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 2.542 AU it takes 4.05 yr to circle the Sun.
Orbit and dynamics
Between its closest point (0.904 AU) and its farthest (4.18 AU), the heliocentric distance changes by 3.276 AU over every revolution.
One full revolution takes 4.05 yr (1,480 days), computed from the semi-major axis of 2.542 AU.
The high eccentricity (0.644) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.
The orbital plane is tilted 14.46° relative to the ecliptic.
By the vis-viva equation its orbital speed rises to 40.2 km/s at perihelion and falls to 8.7 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 = 20.6 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.27 km.
Observation record and orbit quality
Astrometry from 46 individual observations underpins this orbit; the fit leaves an RMS residual of 0.4924 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
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.
