SpaceAtlas Space Object Data
NASA JPL SBDB · 2018 PP9

2018 PP9

2018 PP9 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.654 AU it takes 2.13 yr to circle the Sun.

Apollo Observations: 36
Orbital Period · P
2.13 yr
v(q)
35 km/s
v(Q)
15.3 km/s
Diameter · ≈
0.02 km
TJ
4.18
Eccentricity · e
0.3901

Orbit and dynamics

The path is an ellipse reaching 1.009 AU from the Sun at perihelion and 2.299 AU at aphelion, a radial span of 1.29 AU.

Applying Kepler's third law to a = 1.654 AU gives an orbital period of 2.13 yr, or about 777 days.

An eccentricity of 0.39 makes the orbit moderately elongated.

Its inclination of 2.29° keeps it close to the plane of the ecliptic.

By the vis-viva equation its orbital speed rises to 35 km/s at perihelion and falls to 15.3 km/s at aphelion.

Size and surface

No direct size measurement is available; from an absolute magnitude of H = 25.8 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.02 km.

Observation record and orbit quality

The current orbit solution is based on 36 observations and has a weighted RMS residual of 0.3698 arcseconds.

Condition code U = 6 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
1.654 AU
Eccentricity
0.3901
Perihelion
1.009 AU
Aphelion
2.299225 AU
Inclination
2.29°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
252.57°

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-Aug-28 10:04 0.032138 AU
4807754 km
8.96 km/s
2050-May-27 04:11 0.282145 AU
42208218 km
15.77 km/s
2052-Sep-15 05:15 0.304944 AU
45618933 km
16.29 km/s
2067-Jun-15 20:13 0.078084 AU
11681155 km
8.61 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
25.8

Orbit Quality

RMS
0.36981
Condition
6
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.