SpaceAtlas Space Object Data
NASA JPL SBDB · 2015 HB177

2015 HB177

2015 HB177 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.074 AU it takes 1.11 yr to circle the Sun.

Apollo Observations: 78
Orbital Period · P
1.11 yr
v(q)
41.9 km/s
v(Q)
19.7 km/s
Diameter · ≈
0.04 km
TJ
5.69
Eccentricity · e
0.3591

Orbit and dynamics

Between its closest point (0.688 AU) and its farthest (1.46 AU), the heliocentric distance changes by 0.772 AU over every revolution.

One full revolution takes 1.11 yr (407 days), computed from the semi-major axis of 1.074 AU.

An eccentricity of 0.359 makes the orbit moderately elongated.

Its inclination of 1.62° keeps it close to the plane of the ecliptic.

By the vis-viva equation its orbital speed rises to 41.9 km/s at perihelion and falls to 19.7 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 = 24.62 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.04 km.

Observation record and orbit quality

Astrometry from 78 individual observations underpins this orbit; the fit leaves an RMS residual of 0.4868 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
1.074 AU
Eccentricity
0.3591
Perihelion
0.688 AU
Aphelion
1.459673 AU
Inclination
1.62°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
282.49°

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
2035-May-22 03:51 0.147408 AU
22051854 km
6.97 km/s
2056-Nov-19 07:22 0.186145 AU
27846890 km
5.91 km/s
2066-Nov-30 01:58 0.150726 AU
22548214 km
6.76 km/s
2076-Dec-01 16:27 0.112647 AU
16851746 km
7.95 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
24.62

Orbit Quality

RMS
0.48681
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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