SpaceAtlas Space Object Data
NASA JPL SBDB · 2015 OT78

2015 OT78

2015 OT78 is an Amor-type near-Earth asteroid that approaches Earth from beyond our orbit without crossing it, orbiting the Sun at 2.303 AU once every 3.49 yr.

Amor Observations: 161
Orbital Period · P
3.49 yr
v(q)
33.3 km/s
v(Q)
11.6 km/s
Diameter · ≈
0.12 km
TJ
3.41
Eccentricity · e
0.4835

Orbit and dynamics

The path is an ellipse reaching 1.189 AU from the Sun at perihelion and 3.417 AU at aphelion, a radial span of 2.228 AU.

Applying Kepler's third law to a = 2.303 AU gives an orbital period of 3.49 yr, or about 1,277 days.

The high eccentricity (0.483) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

The orbital plane is tilted 10.23° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 33.3 km/s at perihelion and falls to 11.6 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 = 22.32 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.12 km.

Observation record and orbit quality

The current orbit solution is based on 161 observations and has a weighted RMS residual of 0.3914 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
2.303 AU
Eccentricity
0.4835
Perihelion
1.189 AU
Aphelion
3.416501 AU
Inclination
10.23°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
32.71°

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-13 04:26 0.195222 AU
29204777 km
6.92 km/s
2036-Aug-12 18:42 0.200737 AU
30029765 km
7.03 km/s
2043-Aug-11 15:59 0.222713 AU
33317397 km
7.70 km/s
2050-Aug-08 07:14 0.306493 AU
45850682 km
9.38 km/s
2057-Aug-06 02:57 0.396515 AU
59317763 km
11.01 km/s
2064-Aug-05 13:14 0.435946 AU
65216625 km
11.76 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
22.32

Orbit Quality

RMS
0.39142
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.