SpaceAtlas Space Object Data
NASA JPL SBDB · 2017 HJ49

2017 HJ49

2017 HJ49 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.353 AU it takes 1.57 yr to circle the Sun.

Apollo Observations: 51
Orbital Period · P
1.57 yr
v(q)
40.6 km/s
v(Q)
16.2 km/s
Diameter · ≈
0.09 km
TJ
4.76
Eccentricity · e
0.4304

Orbit and dynamics

Between its closest point (0.771 AU) and its farthest (1.935 AU), the heliocentric distance changes by 1.164 AU over every revolution.

One full revolution takes 1.57 yr (575 days), computed from the semi-major axis of 1.353 AU.

The high eccentricity (0.43) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

The orbital plane is tilted 6.47° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 40.6 km/s at perihelion and falls to 16.2 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

No direct size measurement is available; from an absolute magnitude of H = 23.07 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.09 km.

Observation record and orbit quality

Astrometry from 51 individual observations underpins this orbit; the fit leaves an RMS residual of 0.5975 arcseconds.

Condition code U = 1 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
1.353 AU
Eccentricity
0.4304
Perihelion
0.771 AU
Aphelion
1.935331 AU
Inclination
6.47°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
335.48°

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
2028-Apr-08 08:42 0.088468 AU
13234693 km
13.70 km/s
2035-Nov-14 00:36 0.085472 AU
12786400 km
9.63 km/s
2039-Apr-20 04:22 0.280686 AU
41990041 km
19.86 km/s
2047-Jan-06 22:53 0.225643 AU
33755722 km
10.28 km/s
2047-Apr-29 05:07 0.447344 AU
66921656 km
7.22 km/s
2054-Oct-14 08:14 0.381880 AU
57128490 km
23.11 km/s
2058-Mar-03 16:58 0.186245 AU
27861784 km
8.29 km/s
2065-Oct-28 11:37 0.112000 AU
16754933 km
15.19 km/s
2069-Apr-09 07:06 0.091890 AU
13746505 km
13.87 km/s
2076-Nov-20 23:05 0.124763 AU
18664239 km
8.83 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
23.07

Orbit Quality

RMS
0.59752
Condition
1
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.

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