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Asteroid Near-Earth Potentially hazardous

494999

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494999 (2010 JU39)

Where is it now

Distance from Sun
0.691 AU
True anomaly
96.98°
Distance from Earth
1.368 AU
As of
21 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 — 0.995 AU from the Sun Earth 494999 — 0.691 AU from the Sun 494999
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. 494999 is 1.368 AU from Earth today (11.4 light-minutes).

In the sky

Right ascension
12h 31m 03s
Declination
+10° 54′ 53″
Constellation
Virgo
Distance from Earth
1.37 AU
Elongation from the Sun
28.97° — 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
0.919 AU
Eccentricity
0.546
Inclination
36.22°
Orbital period
321.9 days
Perihelion
0.417 AU
Aphelion
1.421 AU
Longitude of ascending node
95.16°
Argument of periapsis
311.38°
Epoch · J2000
2461200.5
Orbit class · ATE
Aten
Earth MOID · 1.9 LD
0.0048 AU
Tisserand (Jupiter)
6.229

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
267
Data arc
23.06 years
First observed
7 June 2003
Last observed
28 June 2026
Residual RMS
0.45 ″
Solution · Otto Matic
21 September 2026

Physical properties

Rotation period
30.2 hours

Visual & observation

Absolute magnitude (H)
19.69

Discovery & classification

Discovered by
Mt. Lemmon Survey
Discovery date
9 May 2010
Discovery site
Mount Lemmon

Also known as 2010 JU39

Aten Near-Earth Object Potentially Hazardous Asteroid

Close approaches 26 on record

Flyby geometry
Ecliptic flyby of 494999 at 2034-06-25 10:03 UTC Top-down view of the ecliptic, Earth at the centre, for the 2034-06-25 10:03 UTC close approach of 494999. Catalogue miss distance 18.7 LD · 7.18 × 10⁶ km. The curve is the geocentric path from 2034-06-22 to 2034-06-28, 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 23 Jun 28 Jun 18.7 LD · 7.18 × 10⁶ km 2034-06-25 10:03 UTC Earth Moon Heliocentric, approximate

Top-down view of the ecliptic, Earth at the centre, for the 2034-06-25 10:03 UTC close approach of 494999. Catalogue miss distance 18.7 LD · 7.18 × 10⁶ km. The curve is the geocentric path from 2034-06-22 to 2034-06-28, 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
2034-06-25 10:03:00 Earth 0.048 AU 18.7 LD 24.1 km/s
2049-06-20 06:18:00 Earth 0.1874 AU 72.9 LD 27.5 km/s
2056-06-28 07:24:00 Earth 0.0716 AU 27.8 LD 21.6 km/s
2071-06-25 19:58:00 Earth 0.0474 AU 18.4 LD 24.1 km/s
2086-06-20 04:29:00 Earth 0.1996 AU 77.7 LD 27.8 km/s
2093-06-28 06:30:00 Earth 0.0538 AU 21.0 LD 21.9 km/s
2108-06-25 12:58:00 Earth 0.0687 AU 26.8 LD 24.6 km/s
2115-07-01 22:31:00 Earth 0.185 AU 72.0 LD 19.6 km/s
2130-06-29 10:35:00 Earth 0.0451 AU 17.6 LD 22.1 km/s
2145-06-26 02:50:00 Earth 0.0632 AU 24.6 LD 24.4 km/s

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

Sources