SpaceAtlas Space Object Data
NASA JPL SBDB · 2013 XY21

2013 XY21

2013 XY21 is an Amor-type near-Earth asteroid that approaches Earth from beyond our orbit without crossing it, orbiting the Sun at 2.674 AU once every 4.37 yr.

Amor Observations: 91
Orbital Period · P
4.37 yr
v(q)
32.8 km/s
v(Q)
10.1 km/s
Diameter · ≈
0.57 km
TJ
3.05
Eccentricity · e
0.5293

Orbit and dynamics

Between its closest point (1.259 AU) and its farthest (4.089 AU), the heliocentric distance changes by 2.83 AU over every revolution.

One full revolution takes 4.37 yr (1,597 days), computed from the semi-major axis of 2.674 AU.

The high eccentricity (0.529) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

A steep inclination of 25.19° carries it well above and below the ecliptic plane.

By the vis-viva equation its orbital speed rises to 32.8 km/s at perihelion and falls to 10.1 km/s at aphelion.

Its perihelion lies just outside Earth's orbit, which is why it is classed as Earth-approaching rather than Earth-crossing.

Size and surface

No direct size measurement is available; from an absolute magnitude of H = 18.99 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.57 km.

Observation record and orbit quality

Astrometry from 91 individual observations underpins this orbit; the fit leaves an RMS residual of 0.6142 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
2.674 AU
Eccentricity
0.5293
Perihelion
1.259 AU
Aphelion
4.089348 AU
Inclination
25.19°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
287.61°

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

No close approaches to Earth are currently on record for this object.

Physical Parameters

Diameter
— km
Albedo
—
Density
— g/cm³
Rotation Period
— h
Absolute Magnitude
18.99

Orbit Quality

RMS
0.61419
Condition
0
Orbit ID
—
Data source: NASA JPL Small-Body Database . 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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