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Asteroid Near-Earth

143624

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143624 (2003 HM16)

Where is it now

Distance from Sun
3.078 AU
True anomaly
173.83°
Distance from Earth
2.385 AU
As of
11 October 2026

Two-body Kepler propagation — accurate to ~0.1% for major planets over decades, less so for highly-perturbed bodies. Use JPL Horizons for high precision.

Orbit of Mercury Orbit of Venus Orbit of Mars Sun Earth — 0.998 AU from the Sun Earth 143624 — 3.078 AU from the Sun 143624
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. 143624 is 2.385 AU from Earth today (19.8 light-minutes).

In the sky

Right ascension
04h 36m 34s
Declination
-07° 53′ 32″
Constellation
Eridanus
Distance from Earth
2.38 AU
Elongation from the Sun
126.35° — well clear of the Sun

Visible from both hemispheres.

From your location

See how high it is right now, whether it is up after civil twilight, and when it rises and sets where you are.

How do I find my coordinates?

Google Maps on a computer

  1. Right-click the spot where you'll be observing.
  2. The first line of the menu is the coordinates, e.g. 51.50722, -0.12758 — click it and they're copied.
  3. Paste them above.

Google Maps on a phone

  1. Press and hold the spot to drop a pin.
  2. The coordinates appear in the search bar (or on the pin's card) — tap to copy, then paste above.

A full Google Maps link works too, but the short maps.app.goo.gl share links don't carry coordinates — copy the numbers instead. We round to about a kilometre; that's all the sky calculation needs.

Know your what3words address? Paste it, e.g. ///filled.count.soap. This is optional — the three words are sent to what3words to convert them, and we don't store the address or the result.

Your location stays in your browser and is sent only for this calculation. Using a what3words address is optional; if you do, the three words go to what3words to be converted and we don't record them. Set a location first, then you can save an email alert for this object. See our privacy policy.

Two-body approximation, good to about a degree for the planets — enough to find the constellation and know whether it is up.

Orbital elements

Semi-major axis
1.966 AU
Eccentricity
0.5774
Inclination
35.54°
Orbital period
2.76 years
Perihelion
0.831 AU
Aphelion
3.102 AU
Longitude of ascending node
195.83°
Argument of periapsis
47.19°
Epoch · J2000
2461200.5
Orbit class · APO
Apollo
Earth MOID · 20.1 LD
0.0517 AU
Tisserand (Jupiter)
3.463

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
1,624
Data arc
23.4 years
First observed
27 April 2003
Last observed
20 September 2026
Residual RMS
0.49 ″
Solution · Otto Matic
21 September 2026

Physical properties

Mean radius
1.07 km
Rotation period
32.1 hours

Visual & observation

Geometric albedo
0.169
Absolute magnitude (H)
15.91

Discovery & classification

Discovered by
LINEAR
Discovery date
27 April 2003
Discovery site
Socorro

Also known as 2003 HM16

Apollo Near-Earth Object

Close approaches 7 on record

Flyby geometry
Ecliptic flyby of 143624 at 2039-03-27 10:02 UTC Top-down view of the ecliptic, Earth at the centre, for the 2039-03-27 10:02 UTC close approach of 143624. Catalogue miss distance 54.4 LD · 2.09 × 10⁷ km. The curve is the geocentric path from 2039-03-24 to 2039-03-30, with a mark at UTC midnights and an arrow for the direction of motion. The circle is the Moon’s mean orbit; the Moon is plotted at closest approach. A ray shows the Sun’s direction. The labelled distance is the full separation. The drawn radius is the part that lies in the ecliptic plane. The path is a geocentric ecliptic ephemeris from JPL Horizons. The Moon’s position is approximate. The inset is a heliocentric view and is approximate. Sun 54.4 LD · 2.09 × 10⁷ km 2039-03-27 10:02 UTC Earth Moon Heliocentric, approximate

Top-down view of the ecliptic, Earth at the centre, for the 2039-03-27 10:02 UTC close approach of 143624. Catalogue miss distance 54.4 LD · 2.09 × 10⁷ km. The curve is the geocentric path from 2039-03-24 to 2039-03-30, with a mark at UTC midnights and an arrow for the direction of motion. The circle is the Moon’s mean orbit; the Moon is plotted at closest approach. A ray shows the Sun’s direction. The labelled distance is the full separation. The drawn radius is the part that lies in the ecliptic plane. The path is a geocentric ecliptic ephemeris from JPL Horizons. The Moon’s position is approximate. The inset is a heliocentric view and is approximate.

JPL Horizons

When (UTC) Body Distance Lunar distances Relative speed
2039-03-27 10:02:00 Earth 0.1398 AU 54.4 LD 26.1 km/s
2050-04-04 03:27:00 Earth 0.0529 AU 20.6 LD 23.9 km/s
2141-04-03 15:35:00 Earth 0.0561 AU 21.8 LD 24 km/s
2152-04-16 07:00:00 Earth 0.1977 AU 76.9 LD 21.8 km/s

Next ten from today. 1 lunar distance = 384,400 km. Source: JPL close-approach data.

Sources