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Asteroid Near-Earth

85818

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85818 (1998 XM4)

Where is it now

Distance from Sun
1.801 AU
True anomaly
234.84°
Distance from Earth
1.147 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 85818 — 1.801 AU from the Sun 85818
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. 85818 is 1.147 AU from Earth today (9.5 light-minutes).

In the sky

Right ascension
05h 33m 49s
Declination
+28° 33′ 02″
Constellation
Taurus
Distance from Earth
1.14 AU
Elongation from the Sun
114.7° — well clear of the Sun

Favours the northern hemisphere; low or below the horizon from far south.

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
1.657 AU
Eccentricity
0.4161
Inclination
62.72°
Orbital period
778.8 days
Perihelion
0.967 AU
Aphelion
2.346 AU
Longitude of ascending node
235.64°
Argument of periapsis
301.21°
Epoch · J2000
2461200.5
Orbit class · APO
Apollo
Earth MOID · 42.7 LD
0.1098 AU
Tisserand (Jupiter)
3.611

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
1,712
Data arc
33.37 years
First observed
24 May 1993
Last observed
7 October 2026
Residual RMS
0.47 ″
Solution · Otto Matic
8 October 2026

Physical properties

Mean radius
1.01 km
Rotation period
19.45 hours

Visual & observation

Geometric albedo
0.168
Absolute magnitude (H)
15.42
Spectral type (SMASS)
S

Discovery & classification

Discovered by
LINEAR
Discovery date
10 December 1998
Discovery site
Socorro

Also known as 1998 XM4

Apollo Near-Earth Object

Close approaches 8 on record

Flyby geometry
Ecliptic flyby of 85818 at 2027-05-18 07:26 UTC Top-down view of the ecliptic, Earth at the centre, for the 2027-05-18 07:26 UTC close approach of 85818. Catalogue miss distance 49.0 LD · 1.89 × 10⁷ km. The curve is the geocentric path from 2027-05-15 to 2027-05-21, 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 49.0 LD · 1.89 × 10⁷ km 2027-05-18 07:26 UTC Earth Moon Heliocentric, approximate

Top-down view of the ecliptic, Earth at the centre, for the 2027-05-18 07:26 UTC close approach of 85818. Catalogue miss distance 49.0 LD · 1.89 × 10⁷ km. The curve is the geocentric path from 2027-05-15 to 2027-05-21, 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
2027-05-18 07:26:00 Earth 0.126 AU 49.0 LD 33.3 km/s
2059-05-15 20:38:00 Earth 0.1134 AU 44.1 LD 32.6 km/s
2091-05-13 10:08:00 Earth 0.1478 AU 57.5 LD 32 km/s
2140-05-21 10:02:00 Earth 0.1823 AU 70.9 LD 33.9 km/s
2172-05-18 14:34:00 Earth 0.1336 AU 52.0 LD 33.1 km/s

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

Sources