SpaceAtlas Space Object Data
NASA JPL SBDB · 2021 CT8

2021 CT8

2021 CT8 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 2.229 AU it takes 3.33 yr to circle the Sun.

Apollo Observations: 86
Orbital Period · P
3.33 yr
v(q)
52.4 km/s
v(Q)
7.6 km/s
Diameter · ≈
0.34 km
TJ
3.19
Eccentricity · e
0.7469

Orbit and dynamics

The path is an ellipse reaching 0.564 AU from the Sun at perihelion and 3.894 AU at aphelion, a radial span of 3.33 AU.

Applying Kepler's third law to a = 2.229 AU gives an orbital period of 3.33 yr, or about 1,216 days.

The high eccentricity (0.747) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

The orbital plane is tilted 11.37° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 52.4 km/s at perihelion and falls to 7.6 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 = 20.12 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.34 km.

Observation record and orbit quality

The current orbit solution is based on 86 observations and has a weighted RMS residual of 0.5958 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
2.229 AU
Eccentricity
0.7469
Perihelion
0.564 AU
Aphelion
3.89384 AU
Inclination
11.37°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
184.85°

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
2031-Apr-10 14:20 0.220693 AU
33015198 km
19.67 km/s
2041-Mar-31 00:31 0.188340 AU
28175219 km
23.34 km/s
2044-Oct-21 15:19 0.388738 AU
58154402 km
33.32 km/s
2051-Mar-28 22:32 0.198033 AU
29625254 km
25.00 km/s
2054-Oct-23 16:38 0.425936 AU
63719189 km
34.39 km/s
2061-Apr-01 02:10 0.184300 AU
27570919 km
23.18 km/s
2064-Oct-25 06:46 0.463764 AU
69378090 km
35.69 km/s
2071-Apr-03 18:34 0.183906 AU
27511918 km
22.33 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
20.12

Orbit Quality

RMS
0.59582
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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