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Asteroid Near-Earth

143947

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143947 (2003 YQ117)

Where is it now

Distance from Sun
2.892 AU
True anomaly
150.31°
Distance from Earth
3.543 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 143947 — 2.892 AU from the Sun 143947
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. 143947 is 3.543 AU from Earth today (29.5 light-minutes).

In the sky

Right ascension
10h 16m 08s
Declination
-06° 49′ 00″
Constellation
Sextans
Distance from Earth
3.54 AU
Elongation from the Sun
43.19° — near the Sun — look low at dusk or dawn

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
2.182 AU
Eccentricity
0.6543
Inclination
21.03°
Orbital period
3.22 years
Perihelion
0.754 AU
Aphelion
3.61 AU
Longitude of ascending node
217.48°
Argument of periapsis
135.73°
Epoch · J2000
2461200.5
Orbit class · APO
Apollo
Earth MOID · 40.2 LD
0.1032 AU
Tisserand (Jupiter)
3.299

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
2,251
Data arc
24.02 years
First observed
15 March 2002
Last observed
21 March 2026
Residual RMS
0.46 ″
Solution · Otto Matic
22 March 2026

Physical properties

Rotation period
36.4 hours

Visual & observation

Absolute magnitude (H)
15.36

Discovery & classification

Discovered by
NEAT
Discovery date
26 December 2003
Discovery site
Haleakala

Also known as 2003 YQ117

Apollo Near-Earth Object

Close approaches 9 on record

Flyby geometry
Ecliptic flyby of 143947 at 2051-11-06 15:11 UTC Top-down view of the ecliptic, Earth at the centre, for the 2051-11-06 15:11 UTC close approach of 143947. Catalogue miss distance 47.6 LD · 1.83 × 10⁷ km. The curve is the geocentric path from 2051-11-03 to 2051-11-09, 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. At closest approach the object is south of the ecliptic. The path is a geocentric ecliptic ephemeris from JPL Horizons. The inset is a heliocentric view and is approximate. Sun 47.6 LD · 1.83 × 10⁷ km 2051-11-06 15:11 UTC Earth Moon Heliocentric, approximate

Top-down view of the ecliptic, Earth at the centre, for the 2051-11-06 15:11 UTC close approach of 143947. Catalogue miss distance 47.6 LD · 1.83 × 10⁷ km. The curve is the geocentric path from 2051-11-03 to 2051-11-09, 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. At closest approach the object is south of the ecliptic. The path is a geocentric ecliptic ephemeris from JPL Horizons. The inset is a heliocentric view and is approximate.

JPL Horizons

When (UTC) Body Distance Lunar distances Relative speed
2029-04-10 04:18:00 Venus 0.1126 AU 43.8 LD 19.5 km/s
2051-11-06 15:11:00 Earth 0.1223 AU 47.6 LD 19 km/s
2080-10-28 13:23:00 Earth 0.1642 AU 63.9 LD 18.2 km/s
2084-01-10 04:13:00 Venus 0.1153 AU 44.9 LD 19.6 km/s
2138-10-10 05:56:00 Venus 0.125 AU 48.6 LD 18.5 km/s
2183-11-23 16:53:00 Earth 0.1928 AU 75.0 LD 23.5 km/s

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

Sources