SpaceAtlas Space Object Data
NASA JPL SBDB · 2018 PM9

2018 PM9

2018 PM9 is an Amor-type near-Earth asteroid that approaches Earth from beyond our orbit without crossing it, orbiting the Sun at 1.296 AU once every 1.48 yr.

Amor Observations: 51
Orbital Period · P
1.48 yr
v(q)
31.1 km/s
v(Q)
22 km/s
Diameter · ≈
0.09 km
TJ
4.98
Eccentricity · e
0.1714

Orbit and dynamics

The path is an ellipse reaching 1.074 AU from the Sun at perihelion and 1.518 AU at aphelion, a radial span of 0.444 AU.

Applying Kepler's third law to a = 1.296 AU gives an orbital period of 1.48 yr, or about 539 days.

An eccentricity of 0.171 makes the orbit moderately elongated.

The orbital plane is tilted 12.59° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 31.1 km/s at perihelion and falls to 22 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 = 22.94 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.09 km.

Observation record and orbit quality

The current orbit solution is based on 51 observations and has a weighted RMS residual of 0.443 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
1.296 AU
Eccentricity
0.1714
Perihelion
1.074 AU
Aphelion
1.518134 AU
Inclination
12.59°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
86.81°

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
2046-Aug-11 01:45 0.132752 AU
19859407 km
6.53 km/s
2077-Aug-13 00:19 0.099454 AU
14878130 km
7.26 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
22.94

Orbit Quality

RMS
0.44299
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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