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Asteroid Near-Earth

404108

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404108 (2012 SF51)

Where is it now

Distance from Sun
3.805 AU
True anomaly
161.72°
Distance from Earth
3.385 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 404108 — 3.805 AU from the Sun 404108
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. 404108 is 3.385 AU from Earth today (28.2 light-minutes).

In the sky

Right ascension
20h 53m 45s
Declination
-33° 25′ 01″
Constellation
Microscopium
Distance from Earth
3.4 AU
Elongation from the Sun
106.83° — well clear of the Sun

Favours the southern hemisphere; low or below the horizon from far north.

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
2.505 AU
Eccentricity
0.687
Inclination
20.79°
Orbital period
3.97 years
Perihelion
0.784 AU
Aphelion
4.227 AU
Longitude of ascending node
1.13°
Argument of periapsis
156.63°
Epoch · J2000
2461200.5
Orbit class · APO
Apollo
Earth MOID · 63.8 LD
0.164 AU
Tisserand (Jupiter)
3.02

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
494
Data arc
33.94 years
First observed
23 September 1992
Last observed
3 September 2026
Residual RMS
0.52 ″
Solution · Otto Matic
4 September 2026

Visual & observation

Absolute magnitude (H)
15.45

Discovery & classification

Discovered by
WISE
Discovery date
13 May 2010
Discovery site
WISE

Also known as 2012 SF51 · 2010 JG123

Apollo Near-Earth Object

Close approaches 10 on record

Flyby geometry
Ecliptic flyby of 404108 at 2073-04-12 22:08 UTC Top-down view of the ecliptic, Earth at the centre, for the 2073-04-12 22:08 UTC close approach of 404108. Catalogue miss distance 63.8 LD · 2.45 × 10⁷ km. The curve is the geocentric path from 2073-04-09 to 2073-04-15, 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 63.8 LD · 2.45 × 10⁷ km 2073-04-12 22:08 UTC Earth Moon Heliocentric, approximate

Top-down view of the ecliptic, Earth at the centre, for the 2073-04-12 22:08 UTC close approach of 404108. Catalogue miss distance 63.8 LD · 2.45 × 10⁷ km. The curve is the geocentric path from 2073-04-09 to 2073-04-15, 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
2029-07-06 11:21:00 Venus 0.0773 AU 30.1 LD 16.6 km/s
2073-04-12 22:08:00 Earth 0.164 AU 63.8 LD 19.4 km/s
2077-04-05 18:47:00 Earth 0.1554 AU 60.5 LD 18.7 km/s
2081-03-14 09:35:00 Venus 0.14 AU 54.5 LD 18.1 km/s
2081-03-25 08:30:00 Earth 0.1689 AU 65.7 LD 18.2 km/s
2085-03-15 02:11:00 Earth 0.193 AU 75.1 LD 18.1 km/s
2089-03-05 20:20:00 Venus 0.0874 AU 34.0 LD 15.8 km/s
2184-07-20 14:04:00 Venus 0.0989 AU 38.5 LD 17.7 km/s

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

Sources