SpaceAtlas Space Object Data
NASA JPL SBDB · 2015 XT128

2015 XT128

2015 XT128 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.478 AU it takes 1.80 yr to circle the Sun.

Apollo Observations: 129
Orbital Period · P
1.80 yr
v(q)
38.8 km/s
v(Q)
15.5 km/s
Diameter · ≈
0.14 km
TJ
4.48
Eccentricity · e
0.43

Orbit and dynamics

The path is an ellipse reaching 0.842 AU from the Sun at perihelion and 2.114 AU at aphelion, a radial span of 1.272 AU.

Applying Kepler's third law to a = 1.478 AU gives an orbital period of 1.80 yr, or about 656 days.

The high eccentricity (0.43) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

The orbital plane is tilted 5.86° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 38.8 km/s at perihelion and falls to 15.5 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 = 22.1 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.14 km.

Observation record and orbit quality

The current orbit solution is based on 129 observations and has a weighted RMS residual of 0.5405 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
1.478 AU
Eccentricity
0.43
Perihelion
0.842 AU
Aphelion
2.11354 AU
Inclination
5.86°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
244.6°

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
2034-Feb-08 23:09 0.081306 AU
12163158 km
9.36 km/s
2043-Jan-29 12:03 0.052278 AU
7820621 km
10.92 km/s
2052-Jan-21 06:11 0.107411 AU
16068518 km
13.57 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
22.1

Orbit Quality

RMS
0.54049
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.