SpaceAtlas Space Object Data
NASA JPL SBDB · 2021 RO1

2021 RO1

2021 RO1 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.079 AU it takes 1.12 yr to circle the Sun.

Apollo Observations: 80
Orbital Period · P
1.12 yr
v(q)
35.7 km/s
v(Q)
23 km/s
Diameter · ≈
0.1 km
TJ
5.7
Eccentricity · e
0.2156

Orbit and dynamics

Between its closest point (0.846 AU) and its farthest (1.312 AU), the heliocentric distance changes by 0.466 AU over every revolution.

One full revolution takes 1.12 yr (409 days), computed from the semi-major axis of 1.079 AU.

An eccentricity of 0.216 makes the orbit moderately elongated.

The orbital plane is tilted 8.13° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 35.7 km/s at perihelion and falls to 23 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 = 22.73 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.1 km.

Observation record and orbit quality

Astrometry from 80 individual observations underpins this orbit; the fit leaves an RMS residual of 0.5183 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
1.079 AU
Eccentricity
0.2156
Perihelion
0.846 AU
Aphelion
1.311632 AU
Inclination
8.13°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
343.69°

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
2030-Oct-14 03:01 0.245357 AU
36704882 km
12.38 km/s
2031-Aug-04 05:44 0.297818 AU
44552889 km
7.06 km/s
2032-Mar-30 05:05 0.099634 AU
14905103 km
7.75 km/s
2039-Oct-07 03:16 0.408749 AU
61148045 km
17.62 km/s
2040-Aug-24 19:18 0.259417 AU
38808260 km
6.72 km/s
2041-Feb-20 19:21 0.118344 AU
17703973 km
6.61 km/s
2049-Sep-20 12:25 0.190330 AU
28472909 km
5.76 km/s
2050-Jan-04 07:07 0.164121 AU
24552173 km
6.43 km/s
2050-Jun-13 21:55 0.290753 AU
43496012 km
5.73 km/s
2051-Apr-29 16:10 0.435641 AU
65170910 km
18.51 km/s
2058-Oct-18 18:46 0.122951 AU
18393175 km
6.41 km/s
2059-Jul-10 03:34 0.311288 AU
46568079 km
6.79 km/s
2060-Apr-18 06:47 0.263177 AU
39370783 km
13.27 km/s
2067-Oct-15 12:15 0.226464 AU
33878591 km
11.71 km/s
2068-Aug-01 00:01 0.300901 AU
45014154 km
7.09 km/s
2069-Apr-02 15:46 0.111255 AU
16643438 km
8.25 km/s
2076-Oct-07 16:15 0.385573 AU
57680860 km
16.88 km/s
2077-Aug-22 00:55 0.266218 AU
39825628 km
6.82 km/s
2078-Feb-27 06:05 0.110139 AU
16476504 km
6.54 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
22.73

Orbit Quality

RMS
0.51834
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.

Keep exploring

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