SpaceAtlas Space Object Data
NASA JPL SBDB · 2021 CF9

2021 CF9

2021 CF9 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.09 AU it takes 1.14 yr to circle the Sun.

Apollo Observations: 62
Orbital Period · P
1.14 yr
v(q)
38.1 km/s
v(Q)
21.4 km/s
Diameter · ≈
0.2 km
TJ
5.59
Eccentricity · e
0.2808

Orbit and dynamics

Between its closest point (0.784 AU) and its farthest (1.396 AU), the heliocentric distance changes by 0.612 AU over every revolution.

One full revolution takes 1.14 yr (416 days), computed from the semi-major axis of 1.09 AU.

An eccentricity of 0.281 makes the orbit moderately elongated.

A steep inclination of 22.28° carries it well above and below the ecliptic plane.

By the vis-viva equation its orbital speed rises to 38.1 km/s at perihelion and falls to 21.4 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 = 21.23 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.2 km.

Observation record and orbit quality

Astrometry from 62 individual observations underpins this orbit; the fit leaves an RMS residual of 0.5911 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
1.09 AU
Eccentricity
0.2808
Perihelion
0.784 AU
Aphelion
1.396072 AU
Inclination
22.28°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
47.16°

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
2028-Jun-06 19:48 0.362837 AU
54279629 km
20.04 km/s
2029-Sep-12 11:02 0.358638 AU
53651419 km
13.36 km/s
2030-Jan-09 05:51 0.261436 AU
39110283 km
12.50 km/s
2037-Aug-10 04:29 0.254441 AU
38063811 km
14.31 km/s
2038-Jan-21 22:53 0.353477 AU
52879454 km
12.55 km/s
2038-Dec-31 10:20 0.441460 AU
66041434 km
21.83 km/s
2045-Jul-15 06:56 0.170660 AU
25530322 km
14.56 km/s
2046-Feb-04 09:45 0.436395 AU
65283778 km
12.60 km/s
2046-Dec-28 05:12 0.285031 AU
42640092 km
16.72 km/s
2053-Jun-24 11:08 0.214975 AU
32159863 km
16.33 km/s
2054-Feb-18 16:24 0.498232 AU
74534413 km
12.21 km/s
2054-Dec-31 02:50 0.213275 AU
31905426 km
13.46 km/s
2061-Jun-06 20:31 0.366662 AU
54851922 km
20.16 km/s
2062-Sep-11 23:27 0.357043 AU
53412942 km
13.42 km/s
2063-Jan-09 21:40 0.263442 AU
39410396 km
12.49 km/s
2070-Aug-10 14:44 0.254887 AU
38130542 km
14.30 km/s
2071-Jan-22 09:21 0.353940 AU
52948706 km
12.55 km/s
2071-Dec-31 21:45 0.442131 AU
66141820 km
21.87 km/s
2078-Jul-15 20:53 0.170634 AU
25526538 km
14.54 km/s
2079-Feb-04 16:46 0.436099 AU
65239468 km
12.59 km/s
2079-Dec-28 15:18 0.284622 AU
42578910 km
16.74 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
21.23

Orbit Quality

RMS
0.59115
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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