SpaceAtlas Space Object Data
NASA JPL SBDB · 2011 SY120

2011 SY120

2011 SY120 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.217 AU it takes 1.34 yr to circle the Sun.

Apollo Observations: 73
Orbital Period · P
1.34 yr
v(q)
34.1 km/s
v(Q)
21.4 km/s
Diameter · ≈
0.08 km
TJ
5.08
Eccentricity · e
0.2297

Orbit and dynamics

Between its closest point (0.937 AU) and its farthest (1.497 AU), the heliocentric distance changes by 0.56 AU over every revolution.

One full revolution takes 1.34 yr (490 days), computed from the semi-major axis of 1.217 AU.

An eccentricity of 0.23 makes the orbit moderately elongated.

A steep inclination of 31.93° carries it well above and below the ecliptic plane.

By the vis-viva equation its orbital speed rises to 34.1 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 = 23.27 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.08 km.

Observation record and orbit quality

Astrometry from 73 individual observations underpins this orbit; the fit leaves an RMS residual of 0.5849 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
1.217 AU
Eccentricity
0.2297
Perihelion
0.937 AU
Aphelion
1.496545 AU
Inclination
31.93°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
255.21°

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
2050-Oct-06 02:38 0.423548 AU
63361885 km
21.06 km/s
2051-Mar-14 23:54 0.489531 AU
73232809 km
17.95 km/s
2054-Oct-06 21:06 0.321822 AU
48143840 km
18.76 km/s
2055-Mar-15 08:16 0.337947 AU
50556089 km
16.88 km/s
2058-Oct-06 04:38 0.258623 AU
38689440 km
17.19 km/s
2059-Mar-17 21:01 0.188401 AU
28184414 km
16.55 km/s
2062-Oct-04 04:37 0.251806 AU
37669651 km
16.29 km/s
2063-Mar-21 13:04 0.060450 AU
9043210 km
17.17 km/s
2066-Oct-01 05:51 0.292973 AU
43828067 km
15.86 km/s
2067-Mar-25 19:51 0.119645 AU
17898696 km
18.65 km/s
2070-Sep-27 04:29 0.364286 AU
54496352 km
15.74 km/s
2071-Mar-30 23:01 0.263375 AU
39400382 km
20.98 km/s
2074-Sep-21 23:26 0.448068 AU
67030059 km
15.74 km/s
2075-Apr-05 17:03 0.413858 AU
61912300 km
23.93 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
23.27

Orbit Quality

RMS
0.58494
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

Explore asteroids, comets and near-Earth objects with JPL orbital data.