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Asteroid Near-Earth Potentially hazardous

490581

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490581 (2009 WZ104)

Where is it now

Distance from Sun
0.904 AU
True anomaly
242.47°
Distance from Earth
1.716 AU
As of
19 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 490581 — 0.904 AU from the Sun 490581
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. 490581 is 1.716 AU from Earth today (14.3 light-minutes).

In the sky

Right ascension
12h 04m 38s
Declination
-05° 53′ 59″
Constellation
Virgo
Distance from Earth
1.71 AU
Elongation from the Sun
24.09° — 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
0.855 AU
Eccentricity
0.1926
Inclination
9.84°
Orbital period
289 days
Perihelion
0.691 AU
Aphelion
1.02 AU
Longitude of ascending node
263.23°
Argument of periapsis
10.59°
Epoch · J2000
2461200.5
Orbit class · ATE
Aten
Earth MOID · 11.6 LD
0.0299 AU
Tisserand (Jupiter)
6.867

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
1,209
Data arc
19.2 years
First observed
19 November 2005
Last observed
31 January 2025
Residual RMS
0.2 ″
Solution · Otto Matic
4 March 2025

Physical properties

Mean radius
0.12 km
Rotation period
19.3 hours

Visual & observation

Geometric albedo
0.314
Absolute magnitude (H)
20.85

Discovery & classification

Discovered by
CSS
Discovery date
25 November 2009
Discovery site
Catalina

Also known as 2009 WZ104

Aten Near-Earth Object Potentially Hazardous Asteroid

Close approaches 42 on record

Flyby geometry
Ecliptic flyby of 490581 at 2028-12-14 02:16 UTC Top-down view of the ecliptic, Earth at the centre, for the 2028-12-14 02:16 UTC close approach of 490581. Catalogue miss distance 12.4 LD · 4.78 × 10⁶ km. The curve is the geocentric path from 2028-12-11 to 2028-12-17, 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 inset is a heliocentric view and is approximate. Sun 12.4 LD · 4.78 × 10⁶ km 2028-12-14 02:16 UTC Earth Moon Heliocentric, approximate

Top-down view of the ecliptic, Earth at the centre, for the 2028-12-14 02:16 UTC close approach of 490581. Catalogue miss distance 12.4 LD · 4.78 × 10⁶ km. The curve is the geocentric path from 2028-12-11 to 2028-12-17, 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 inset is a heliocentric view and is approximate.

JPL Horizons

When (UTC) Body Distance Lunar distances Relative speed
2028-12-14 02:16:00 Earth 0.032 AU 12.4 LD 6.2 km/s
2043-11-29 22:06:00 Earth 0.106 AU 41.3 LD 8.3 km/s
2048-01-07 01:45:00 Earth 0.0969 AU 37.7 LD 6.6 km/s
2062-12-13 02:37:00 Earth 0.0303 AU 11.8 LD 6.2 km/s
2067-01-20 13:11:00 Earth 0.1994 AU 77.6 LD 9.8 km/s
2077-11-29 08:04:00 Earth 0.1074 AU 41.8 LD 8.3 km/s
2082-01-05 17:31:00 Earth 0.0944 AU 36.7 LD 6.6 km/s
2096-12-08 06:25:00 Earth 0.0338 AU 13.2 LD 6.5 km/s
2101-01-17 15:08:00 Earth 0.1506 AU 58.6 LD 8.1 km/s
2115-12-10 04:53:00 Earth 0.0333 AU 13.0 LD 6.5 km/s

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

Sources