Asteroids

85640 1998OX4 help

Last update: 2026-07-30 09:40 UTC

Orbital Properties

Epoch

61200.0

MJD

Orbit type

Apollo

Perihelion (q)

0.813

Aphelion (Q)

2.348

Eccentricity (e)

0.486

Inclination (i)

4.5

deg

Orbit period (P)

725.7

Earth MOID

0.00078

U parameter

0.0

Next Earth close approach

Date

Nominal distance (from Earth center)

Maximum Brightness

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

mag

Diameter

160 - 400*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

1998-07-26

Observatory

Steward Observatory, Kitt Peak-Spacewatch

ORBIT VISUALISATION TOOLS

External links

Proper elements

Epoch

Near present day

Near middle of observation arc

Orbit properties

Epoch
Semimajor Axis
Eccentricity (e)
Inclination (i)
Long. of Ascending Node (Ω)
Arg. of Perihelion (ω)
Mean Anomaly (M)
Perihelion distance
Aphelion distance
Asc. Node-Earth Sep.
Desc. Node-Earth Sep.
MOID
Orbit Period
U parameter

Value

1-sigma variation

Unit

Epoch

Value

61200.0000

1-sigma variation

Unit

MJD

Semimajor Axis

Value

1.580377

1-sigma variation

1.898E-9

Unit

Eccentricity (e)

Value

0.485677

1-sigma variation

3.421E-8

Unit

Inclination (i)

Value

4.5158

1-sigma variation

6.766E-6

Unit

Long. of Ascending Node (Ω)

Value

299.5618

1-sigma variation

0.0001

Unit

Arg. of Perihelion (ω)

Value

117.3164

1-sigma variation

0.0001

Unit

Mean Anomaly (M)

Value

312.92172

1-sigma variation

0.00001

Unit

Perihelion distance

Value

0.812824

1-sigma variation

Unit

Aphelion distance

Value

2.347929

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.537400

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.003552

1-sigma variation

Unit

MOID

Value

0.000784

1-sigma variation

Unit

Orbit Period

Value

725.6702

1-sigma variation

Unit

U parameter

Value

0.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	3.60226E-18	4.23468E-17	-9.61540E-16	1.54793E-14	-1.42011E-14	-1.39128E-14
e	4.23468E-17	1.17003E-15	-2.72413E-14	3.06586E-13	-2.51789E-13	-1.20274E-13
i	-9.61540E-16	-2.72413E-14	4.57786E-11	4.11175E-10	-4.05717E-10	-1.88398E-13
Ω	1.54793E-14	3.06586E-13	4.11175E-10	5.67342E-9	-5.68259E-9	-3.73531E-11
ω	-1.42011E-14	-2.51789E-13	-4.05717E-10	-5.68259E-9	5.72417E-9	2.01460E-11
M	-1.39128E-14	-1.20274E-13	-1.88398E-13	-3.73531E-11	2.01460E-11	6.72007E-11

Date of computation: 2026-07-30 09:40 UTC

Note: The ASCII file is in a format suitable for Orbfit input.

Download ASCII file:

Physical properties

Rotation Period
Quality
Amplitude
Rotation Direction
Spinvector L
Spinvector B

Rotational properties

Value

Unit

Source

Rotation Period

Value

Unit

Source

[-]

Quality

Value

Unit

Source

[-]

Amplitude

Value

Unit

mag

Source

[-]

Rotation Direction

Value

Unit

Source

[-]

Spinvector L

Value

Unit

Source

[-]

Spinvector B

Value

Unit

Source

[-]

Taxonomy
Taxonomy (all)

Taxonomy

Value

Unit

Source

Taxonomy

Value

Unit

Source

[-]

Taxonomy (all)

Value

Unit

Source

[-]

Absolute Magnitude (H)
Slope Parameter (G)

H / G

Value

Unit

Source

Absolute Magnitude (H)

Value

21.041

Unit

mag

Source

[1]

Slope Parameter (G)

Value

0.15**

Unit

Source

[1]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.05 - 0.25

Unit

Source

[2]

Diameter

Value

160 - 400*

Unit

Source

[2]

Color Index Information

Color Index Information

Value

Unit

Source

Color Index Information

Value

Unit

mag

Source

[-]

Sightings

Sightings

Value

Unit

Source

Sightings

Value

Unit

Source

[-]

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Sources

No.	Name	Additional
[1]	ESA Aegis	ESA orbit determination and impact monitoring system
[2]	Estimation	Estimated from absolute magnitude

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

7584

Unit

Source

[1]

Unobserved

Value

2716

Unit

Source

[1]

Normalized RMS of residuals

Value

0.588818

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

1998-07-26.30244

Unit

Source

[2]

Last Observation

Value

2019-05-01.410555

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

279 (4)

Unit

Source

[1]

Radar Summary

First Observation
Last Observation
Delay (Discarded)
Doppler (Discarded)
Total Optical Observations (Discarded)

Radar

Value

Unit

Source

First Observation

Value

Unit

Source

[-]

Last Observation

Value

Unit

Source

[-]

Delay (Discarded)

Value

0 (0)

Unit

Source

[-]

Doppler (Discarded)

Value

0 (0)

Unit

Source

[-]

Total Radar Observations (Discarded)

Value

0 (0)

Unit

Source

[-]

Note: The ASCII file is in a format suitable for Orbfit input.

Sources

No.	Name	Additional
[1]	ESA Aegis	ESA orbit determination and impact monitoring system
[2]	MPC	Minor Planet Center: https://www.minorplanetcenter.net

Filters

Initial Date: *

Final Date: *

Normalised Only accepted

Max residual (arcsec):

* - these fields are required

Plot

Computation parameters

As seen from:

Initial Date: *

Final Date: *

Output option:

One line per time step

Time step:*

* - these fields are required

Note: Ephemerides requests are limited to a maximum of 1000 points and a final date not exceeding 2040/12/31 00:00.

Close Approaches for 85640 1998OX4 from 1950 to 2126

Body	Date in UTC	Time uncert. in min	Nominal distance in au	Min. possible distance in au	Distance uncert. in au
EARTH	1964-09-01 11:56	2.7	0.1799779	0.1798790	0.0000330
EARTH	1966-09-07 15:41	2.8	0.1014699	0.1013985	0.0000238
EARTH	1968-09-13 07:07	3.0	0.0610730	0.0610687	0.0000014
EARTH	1970-09-22 16:20	4.4	0.0924796	0.0924356	0.0000147
EARTH	1972-10-09 09:50	7.6	0.1448449	0.1448122	0.0000109
EARTH	1974-10-29 03:59	8.3	0.1758051	0.1757923	0.0000043
EARTH	1976-11-15 15:47	7.2	0.1854589	0.1854586	0.0000001
EARTH	1978-12-03 20:41	5.4	0.1737643	0.1737556	0.0000029
EARTH	1980-12-22 11:19	3.1	0.1386923	0.1386790	0.0000044
EARTH	1983-01-09 08:15	< 1 min	0.0786199	0.0786097	0.0000034
EARTH	1985-01-18 08:56	< 1 min	0.0064830	0.0064824	0.0000002
EARTH	1987-01-13 00:01	< 1 min	0.0557508	0.0557499	0.0000003
EARTH	1989-01-02 07:56	< 1 min	0.1077614	0.1077606	0.0000003
EARTH	1990-12-18 16:09	< 1 min	0.1499691	0.1499685	0.0000002
EARTH	1992-12-02 06:12	< 1 min	0.1764737	0.1764733	0.0000001
EARTH	1994-11-18 06:03	< 1 min	0.1875667	0.1875665	0.0000001
EARTH	1996-11-04 06:54	< 1 min	0.1840314	0.1840312	0.0000001
EARTH	1998-10-20 14:04	< 1 min	0.1678011	0.1678009	0.0000001
EARTH	2000-10-04 15:05	< 1 min	0.1378731	0.1378728	0.0000001
EARTH	2002-09-22 17:39	< 1 min	0.0974410	0.0974408	0.0000001
EARTH	2004-09-14 10:21	< 1 s	0.0642889	0.0642887	0.0000001
EARTH	2006-09-09 20:23	< 1 s	0.0711532	0.0711531	0.0000001
EARTH	2008-09-04 17:23	< 1 s	0.1202276	0.1202274	0.0000001
EARTH	2010-08-31 13:36	< 1 s	0.1885896	0.1885893	0.0000001

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
39.03873274	14.37427337	0.00078350	MINIMUM
317.62430104	246.49978070	0.06182356	MINIMUM
357.02650485	308.40088783	0.18777783	SADDLE
179.25514390	131.80358776	1.34100619	SADDLE
358.23602664	130.45248555	1.82283416	SADDLE
179.53833523	311.97811647	3.33510709	MAXIMUM

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MOID Plots

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