SpaceAtlas Space Object Data
NASA JPL SBDB · 477491

477491

477491 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 2.257 AU it takes 3.39 yr to circle the Sun.

Apollo Observations: 361
Orbital Period · P
3.39 yr
v(q)
38.4 km/s
v(Q)
10.2 km/s
Diameter · ≈
0.9 km
TJ
3.31
Eccentricity · e
0.5787

Orbit and dynamics

The path is an ellipse reaching 0.951 AU from the Sun at perihelion and 3.563 AU at aphelion, a radial span of 2.612 AU.

Applying Kepler's third law to a = 2.257 AU gives an orbital period of 3.39 yr, or about 1,238 days.

The high eccentricity (0.579) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

A steep inclination of 20.76° carries it well above and below the ecliptic plane.

By the vis-viva equation its orbital speed rises to 38.4 km/s at perihelion and falls to 10.2 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

The measured diameter is 0.74 km, a value from direct size determination rather than from brightness alone.

A geometric albedo of 0.25 points to a comparatively bright, reflective surface.

Observation record and orbit quality

The current orbit solution is based on 361 observations and has a weighted RMS residual of 0.4936 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
2.257 AU
Eccentricity
0.5787
Perihelion
0.951 AU
Aphelion
3.563126 AU
Inclination
20.76°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
299.87°

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
2044-Jan-28 22:28 0.120600 AU
18041473 km
17.28 km/s
2061-Jan-25 09:08 0.095646 AU
14308469 km
16.33 km/s
2078-Jan-27 00:53 0.107017 AU
16009582 km
16.83 km/s

Distances in astronomical units (AU) and kilometres. Source: NASA/JPL CNEOS Close Approach Data API.

Physical Parameters

Diameter
0.739 km
Albedo
0.25
Density
— g/cm³
Rotation Period
— h
Absolute Magnitude
17.99

Orbit Quality

RMS
0.49356
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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