SpaceAtlas Space Object Data
NASA JPL SBDB · 2008 ER

2008 ER

2008 ER belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.215 AU it takes 1.34 yr to circle the Sun.

Apollo Observations: 63
Orbital Period · P
1.34 yr
v(q)
35.1 km/s
v(Q)
20.8 km/s
Diameter · ≈
0.18 km
TJ
5.2
Eccentricity · e
0.257

Orbit and dynamics

The path is an ellipse reaching 0.903 AU from the Sun at perihelion and 1.527 AU at aphelion, a radial span of 0.624 AU.

Applying Kepler's third law to a = 1.215 AU gives an orbital period of 1.34 yr, or about 489 days.

An eccentricity of 0.257 makes the orbit moderately elongated.

The orbital plane is tilted 9.41° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 35.1 km/s at perihelion and falls to 20.8 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 = 21.42 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.18 km.

Observation record and orbit quality

The current orbit solution is based on 63 observations and has a weighted RMS residual of 0.6241 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
1.215 AU
Eccentricity
0.257
Perihelion
0.903 AU
Aphelion
1.527255 AU
Inclination
9.41°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
103.58°

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
2059-Jun-04 06:01 0.167352 AU
25035445 km
8.66 km/s
2063-Jun-27 23:57 0.143978 AU
21538855 km
7.48 km/s
2067-Jul-22 01:34 0.129488 AU
19371122 km
7.69 km/s
2071-Aug-12 08:44 0.111668 AU
16705225 km
7.76 km/s
2075-Sep-01 18:09 0.095192 AU
14240493 km
7.75 km/s
2079-Sep-19 19:54 0.099481 AU
14882198 km
8.39 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
21.42

Orbit Quality

RMS
0.62414
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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