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Asteroid Near-Earth

333478

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333478 (2004 SD20)

Where is it now

Distance from Sun
1.174 AU
True anomaly
206.61°
Distance from Earth
0.785 AU
As of
20 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.

Sun Earth — 0.996 AU from the Sun Earth 333478 — 1.174 AU from the Sun 333478
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. 333478 is 0.785 AU from Earth today (6.5 light-minutes).

In the sky

Right ascension
19h 39m 33s
Declination
-49° 36′ 25″
Constellation
Telescopium
Distance from Earth
0.79 AU
Elongation from the Sun
81.53° — 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
0.875 AU
Eccentricity
0.4649
Inclination
21.33°
Orbital period
299.2 days
Perihelion
0.468 AU
Aphelion
1.282 AU
Longitude of ascending node
46.55°
Argument of periapsis
94.51°
Epoch · J2000
2461200.5
Orbit class · ATE
Aten
Earth MOID · 70.3 LD
0.1805 AU
Tisserand (Jupiter)
6.62

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
253
Data arc
21.82 years
First observed
21 September 2004
Last observed
16 July 2026
Residual RMS
0.34 ″
Solution · Otto Matic
16 July 2026

Visual & observation

Absolute magnitude (H)
18.05

Discovery & classification

Discovered by
Siding Spring Survey
Discovery date
21 September 2004
Discovery site
Siding Spring

Also known as 2004 SD20

Aten Near-Earth Object

Close approaches 67 on record

When (UTC) Body Distance Lunar distances Relative speed
2027-02-28 21:47:00 Venus 0.0772 AU 30.0 LD 22.1 km/s
2029-08-14 15:50:00 Venus 0.0635 AU 24.7 LD 21.3 km/s
2032-01-29 13:08:00 Venus 0.0558 AU 21.7 LD 20.5 km/s
2034-07-15 15:37:00 Venus 0.0535 AU 20.8 LD 20 km/s
2036-12-29 18:10:00 Venus 0.0543 AU 21.1 LD 19.5 km/s
2039-06-15 19:52:00 Venus 0.0583 AU 22.7 LD 19 km/s
2041-11-29 18:41:00 Venus 0.0654 AU 25.4 LD 18.5 km/s
2044-05-15 13:46:00 Venus 0.0762 AU 29.7 LD 17.9 km/s
2046-10-30 02:39:00 Venus 0.0911 AU 35.4 LD 17.2 km/s
2049-04-14 06:43:00 Venus 0.1101 AU 42.8 LD 16.5 km/s

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

Sources