SpaceAtlas Space Object Data
NASA JPL SBDB · 2018 XE4

2018 XE4

2018 XE4 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.593 AU it takes 2.01 yr to circle the Sun.

Apollo Observations: 25
Orbital Period · P
2.01 yr
v(q)
38.2 km/s
v(Q)
14.6 km/s
Diameter · ≈
0.02 km
TJ
4.26
Eccentricity · e
0.4472

Orbit and dynamics

Between its closest point (0.881 AU) and its farthest (2.305 AU), the heliocentric distance changes by 1.424 AU over every revolution.

One full revolution takes 2.01 yr (734 days), computed from the semi-major axis of 1.593 AU.

The high eccentricity (0.447) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

Its inclination of 2.95° keeps it close to the plane of the ecliptic.

By the vis-viva equation its orbital speed rises to 38.2 km/s at perihelion and falls to 14.6 km/s at aphelion.

Because q < 1 AU and Q > 1 AU, this orbit geometrically intersects the region of Earth's orbit.

Size and surface

No direct size measurement is available; from an absolute magnitude of H = 26.4 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.02 km.

Observation record and orbit quality

Astrometry from 25 individual observations underpins this orbit; the fit leaves an RMS residual of 0.7891 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
1.593 AU
Eccentricity
0.4472
Perihelion
0.881 AU
Aphelion
2.30539 AU
Inclination
2.95°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
238.73°

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
2027-Feb-10 19:33 0.113856 AU
17032622 km
8.06 km/s
2029-Mar-01 17:26 0.107473 AU
16077774 km
7.92 km/s
2031-Mar-20 13:41 0.080771 AU
12083214 km
7.97 km/s
2033-Apr-01 12:53 0.051369 AU
7684757 km
9.15 km/s
2035-Apr-09 15:16 0.063345 AU
9476341 km
10.90 km/s
2037-Apr-15 06:09 0.120635 AU
18046787 km
13.03 km/s
2039-Apr-21 10:16 0.198349 AU
29672567 km
15.49 km/s
2041-Apr-26 02:14 0.283733 AU
42445830 km
18.06 km/s
2043-May-01 11:03 0.371851 AU
55628067 km
20.68 km/s
2045-May-05 22:26 0.461473 AU
69035321 km
23.35 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
26.4

Orbit Quality

RMS
0.78914
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.

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