SpaceAtlas Space Object Data
NASA JPL SBDB · 2021 FC

2021 FC

2021 FC is an Aten-type near-Earth asteroid whose orbit lies mostly inside that of Earth, with a semi-major axis of 0.956 AU and a period of 0.94 yr.

Aten Observations: 79
Orbital Period · P
0.94 yr
v(q)
37.1 km/s
v(Q)
25 km/s
Diameter · ≈
0.01 km
TJ
6.28
Eccentricity · e
0.1952

Orbit and dynamics

Between its closest point (0.77 AU) and its farthest (1.143 AU), the heliocentric distance changes by 0.373 AU over every revolution.

One full revolution takes 0.94 yr (342 days), computed from the semi-major axis of 0.956 AU.

An eccentricity of 0.195 makes the orbit moderately elongated.

Its inclination of 3.37° keeps it close to the plane of the ecliptic.

By the vis-viva equation its orbital speed rises to 37.1 km/s at perihelion and falls to 25 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 = 28.25 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.01 km.

Observation record and orbit quality

Astrometry from 79 individual observations underpins this orbit; the fit leaves an RMS residual of 0.4392 arcseconds.

Condition code U = 4 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
0.9563 AU
Eccentricity
0.1952
Perihelion
0.77 AU
Aphelion
1.14297 AU
Inclination
3.37°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
305.44°

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
2035-Mar-21 17:27 0.177909 AU
26614840 km
10.84 km/s
2036-Jan-10 03:04 0.186212 AU
27856960 km
5.25 km/s
2036-May-10 19:59 0.139608 AU
20885044 km
4.47 km/s
2036-Oct-16 23:50 0.201440 AU
30134969 km
6.18 km/s
2037-Jul-26 17:04 0.118144 AU
17674099 km
8.67 km/s
2038-Jul-09 14:01 0.499121 AU
74667449 km
20.23 km/s
2049-Mar-28 19:45 0.350235 AU
52394345 km
16.02 km/s
2050-Mar-20 01:06 0.048542 AU
7261789 km
4.26 km/s
2050-Nov-18 23:02 0.223465 AU
33429898 km
7.03 km/s
2051-Jul-30 23:14 0.059335 AU
8876430 km
4.39 km/s
2052-Jul-14 16:46 0.362942 AU
54295362 km
16.10 km/s
2063-Apr-02 09:07 0.449588 AU
67257345 km
19.09 km/s
2064-Mar-16 07:50 0.046733 AU
6991104 km
6.97 km/s
2064-Dec-10 17:40 0.216518 AU
32390566 km
6.66 km/s
2065-Jun-17 09:11 0.131708 AU
19703217 km
4.10 km/s
2065-Sep-13 07:03 0.151715 AU
22696249 km
4.29 km/s
2066-Jul-21 16:15 0.234228 AU
35039977 km
12.26 km/s
2078-Mar-26 19:44 0.306353 AU
45829786 km
14.78 km/s
2079-Mar-28 03:51 0.075689 AU
11322867 km
3.86 km/s
2079-Nov-14 14:06 0.221312 AU
33107846 km
6.98 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
28.25

Orbit Quality

RMS
0.43924
Condition
4
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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