SpaceAtlas Space Object Data
NASA JPL SBDB · 1999 RN28

1999 RN28

1999 RN28 is an Amor-type near-Earth asteroid that approaches Earth from beyond our orbit without crossing it, orbiting the Sun at 2.169 AU once every 3.19 yr.

Amor Observations: 103
Orbital Period · P
3.19 yr
v(q)
33 km/s
v(Q)
12.4 km/s
Diameter · ≈
0.21 km
TJ
3.54
Eccentricity · e
0.4548

Orbit and dynamics

Between its closest point (1.183 AU) and its farthest (3.155 AU), the heliocentric distance changes by 1.972 AU over every revolution.

One full revolution takes 3.19 yr (1,167 days), computed from the semi-major axis of 2.169 AU.

The high eccentricity (0.455) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

The orbital plane is tilted 8.78° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 33 km/s at perihelion and falls to 12.4 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 = 21.1 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.21 km.

Observation record and orbit quality

Astrometry from 103 individual observations underpins this orbit; the fit leaves an RMS residual of 0.5298 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
2.169 AU
Eccentricity
0.4548
Perihelion
1.183 AU
Aphelion
3.155461 AU
Inclination
8.78°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
141.03°

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
2031-Sep-06 09:45 0.498213 AU
74531568 km
7.45 km/s
2066-Aug-30 14:23 0.298949 AU
44722122 km
8.70 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
21.1

Orbit Quality

RMS
0.52976
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.