SpaceAtlas Space Object Data
NASA JPL SBDB · 2015 HW

2015 HW

2015 HW belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.209 AU it takes 1.33 yr to circle the Sun.

Apollo Observations: 27
Orbital Period · P
1.33 yr
v(q)
36.2 km/s
v(Q)
20.3 km/s
Diameter · ≈
0.03 km
TJ
5.16
Eccentricity · e
0.2829

Orbit and dynamics

Between its closest point (0.867 AU) and its farthest (1.551 AU), the heliocentric distance changes by 0.684 AU over every revolution.

One full revolution takes 1.33 yr (486 days), computed from the semi-major axis of 1.209 AU.

An eccentricity of 0.283 makes the orbit moderately elongated.

A steep inclination of 22.93° carries it well above and below the ecliptic plane.

By the vis-viva equation its orbital speed rises to 36.2 km/s at perihelion and falls to 20.3 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 = 25.7 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.03 km.

Observation record and orbit quality

Astrometry from 27 individual observations underpins this orbit; the fit leaves an RMS residual of 0.6353 arcseconds.

Condition code U = 8 signals a poorly constrained orbit, so its future path should be treated as provisional.

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
1.209 AU
Eccentricity
0.2829
Perihelion
0.867 AU
Aphelion
1.551026 AU
Inclination
22.93°
Orbital Period
— yr
Epoch
2457131.5
Mean Anomaly
50.98°

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

No close approaches to Earth are currently on record for this object.

Physical Parameters

Diameter
— km
Albedo
—
Density
— g/cm³
Rotation Period
— h
Absolute Magnitude
25.7

Orbit Quality

RMS
0.63528
Condition
8
Orbit ID
—
Data source: NASA JPL Small-Body Database . 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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