SpaceAtlas Space Object Data
NASA JPL SBDB · 2018 NM4

2018 NM4

2018 NM4 is an Amor-type near-Earth asteroid that approaches Earth from beyond our orbit without crossing it, orbiting the Sun at 1.692 AU once every 2.20 yr.

Amor Observations: 51
Orbital Period · P
2.20 yr
v(q)
29.6 km/s
v(Q)
17.7 km/s
Diameter · ≈
0.24 km
TJ
4.13
Eccentricity · e
0.2526

Orbit and dynamics

Between its closest point (1.265 AU) and its farthest (2.119 AU), the heliocentric distance changes by 0.854 AU over every revolution.

One full revolution takes 2.20 yr (804 days), computed from the semi-major axis of 1.692 AU.

An eccentricity of 0.253 makes the orbit moderately elongated.

The orbital plane is tilted 17.98° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 29.6 km/s at perihelion and falls to 17.7 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 = 20.85 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.24 km.

Observation record and orbit quality

Astrometry from 51 individual observations underpins this orbit; the fit leaves an RMS residual of 0.5507 arcseconds.

Condition code U = 1 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
1.692 AU
Eccentricity
0.2526
Perihelion
1.265 AU
Aphelion
2.119399 AU
Inclination
17.98°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
202.93°

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
2029-Aug-15 15:27 0.328184 AU
49095663 km
9.61 km/s
2040-Aug-14 00:36 0.308917 AU
46213294 km
9.54 km/s
2051-Aug-13 15:34 0.293923 AU
43970217 km
9.47 km/s
2062-Aug-12 11:15 0.282746 AU
42298148 km
9.42 km/s
2073-Aug-11 11:02 0.274736 AU
41099914 km
9.37 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
20.85

Orbit Quality

RMS
0.55072
Condition
1
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.

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