Asteroids

310842 2003AK18 help

Last update: 2025-09-10 00:30 UTC

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Aten

Perihelion (q)

0.540

Aphelion (Q)

1.214

Eccentricity (e)

0.384

Inclination (i)

7.4

deg

Orbit period (P)

300.0

Earth MOID

0.05641

U parameter

0.2

A₂

-38.2

10^-15au/days²

Next Earth close approach

Date

2026-01-22

Nominal distance (from Earth center)

0.19731

29516609

Maximum Brightness

17.5

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

19.8

mag

Diameter

300 - 700*

Taxonomic type

Rotation period (T)

5.300

Discovery Information

Discovery Date

2003-01-07

Observatory

Lincoln Laboratory ETS, New Mexico

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

61000.0000

1-sigma variation

Unit

MJD

Semimajor Axis

Value

0.876979

1-sigma variation

3.174E-9

Unit

Eccentricity (e)

Value

0.384204

1-sigma variation

5.608E-8

Unit

Inclination (i)

Value

7.4023

1-sigma variation

3.854E-6

Unit

Long. of Ascending Node (Ω)

Value

301.5385

1-sigma variation

1.361E-5

Unit

Arg. of Perihelion (ω)

Value

23.9539

1-sigma variation

1.570E-5

Unit

Mean Anomaly (M)

Value

64.71175

1-sigma variation

0.00002

Unit

Perihelion distance

Value

0.540040

1-sigma variation

Unit

Aphelion distance

Value

1.213917

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

-0.463811

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.167525

1-sigma variation

Unit

MOID

Value

0.056410

1-sigma variation

Unit

Orbit Period

Value

299.9728

1-sigma variation

Unit

U parameter

Value

0.2

1-sigma variation

Unit

A₂

Value

-38.18375

1-sigma variation

4.27228

Unit

10^-15au/days²

Covariance Matrix

	a	e	i	Ω	ω	M	A₂
a	1.00747E-17	-5.88465E-17	3.11831E-15	6.64389E-16	-2.32211E-15	-4.34090E-14	1.33048E-8
e	-5.88465E-17	3.14448E-15	-8.81760E-14	-7.03589E-14	2.04298E-13	-6.83532E-14	-6.06414E-8
i	3.11831E-15	-8.81760E-14	1.48558E-11	-2.69009E-11	9.82466E-12	1.41374E-11	3.94070E-6
Ω	6.64389E-16	-7.03589E-14	-2.69009E-11	1.85363E-10	-1.97503E-10	1.22880E-11	-1.26606E-6
ω	-2.32211E-15	2.04298E-13	9.82466E-12	-1.97503E-10	2.46562E-10	-5.71781E-11	2.64865E-7
M	-4.34090E-14	-6.83532E-14	1.41374E-11	1.22880E-11	-5.71781E-11	2.98849E-10	-5.63180E-5
A₂	1.33048E-8	-6.06414E-8	3.94070E-6	-1.26606E-6	2.64865E-7	-5.63180E-5	1.82524E1

Date of computation: 2025-09-10 00:30 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

5.300

Unit

Source

[3]

[4]

Quality

Value

Unit

Source

[3]

Amplitude

Value

0.19

Unit

mag

Source

[3]

[4]

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

[1]

Taxonomy (all)

Value

Unit

Source

[2]

Absolute Magnitude (H)
Slope Parameter (G)

H / G

Value

Unit

Source

Absolute Magnitude (H)

Value

19.76

19.88

Unit

mag

Source

[5]

[6]

Slope Parameter (G)

Value

0.15**

0.24

Unit

mag

Source

[5]

[7]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.05 - 0.25

Unit

Source

[8]

Diameter

Value

300 - 700*

Unit

Source

[8]

Color Index Information

Color Index Information

Value

Unit

Source

Color Index Information

Value

0.4112

0.2543

0.1569

-0.077

0.079

0.3333

Unit

g-i

g-r

r-i

i-z

r-z

g-z

Source

[1]

Sightings

Sightings

Value

Unit

Source

Sightings

Value

Radar R

Unit

Source

[9]

Download this part as:

Sources

No.	Name	Additional
[1]	EARN	1.) A. V. Sergeyev, B. Carry et al A&A, 658 (2022) A109
[2]	EARN	Earth Asteroids Research Node: https://earn.dlr.de
[3]	EARN	1.) Petr Pravec's Ondrejov NEO Photometric Program Webpage "Prepublished Periods"
[4]	EARN	1.) Pravec, P.; Wolf, M.; Sarounova, L. (2003) http://www.asu.cas.cz/~ppravec/neo.htm
[5]	ESA Aegis	ESA orbit determination and impact monitoring system
[6]	EARN	1.) Pravec, P. et al. (2012) Icarus 221, 365-387 (Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations) 2.) Petr Pravec's Ondrejov NEO Photometric Program Webpage "Prepublished Periods"
[7]	EARN	1.) Pravec, P. et al. (2012) Icarus 221, 365-387 (Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations)
[8]	Estimation	Estimated from absolute magnitude
[9]	EARN	1.) href="http://echo.jpl.nasa.gov/asteroids/index.html">JPL's NEO Radar Detection Program Webpage

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

7023

Unit

Source

[1]

Unobserved

Value

1302

Unit

Source

[1]

Normalized RMS of residuals

Value

0.465847

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2003-01-07.39471

Unit

Source

[2]

Last Observation

Value

2022-03-31.118535

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

604 (8)

Unit

Source

[1]

Radar Summary

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

Radar

Value

Unit

Source

First Observation

Value

2011-12-18

Unit

Source

[3]

Last Observation

Value

2011-12-29

Unit

Source

[3]

Delay (Discarded)

Value

1 (0)

Unit

Source

[1]

Doppler (Discarded)

Value

3 (0)

Unit

Source

[1]

Total Radar Observations (Discarded)

Value

4 (0)

Unit

Source

[1]

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
[3]	JPL Radar Observations	Jet Propulsion Laboratory: https://ssd.jpl.nasa.gov/dat/radar_data_ast.txt

Computation parameters

As seen from:

Initial Date: *

Final Date: *

Output option:

One line per time step

Time step:*

* - these fields are required

Close Approaches for 310842 2003AK18 from 1950 to 2125

Body	Date in UTC	Time uncert. in min	Nominal distance in au	Min. possible distance in au	Distance uncert. in au
EARTH	1952-12-27 21:39	< 1 min	0.0878779	0.0878736	0.0000014
EARTH	1961-12-29 02:17	< 1 min	0.1261110	0.1261062	0.0000016
EARTH	1963-04-01 00:53	< 1 min	0.1784438	0.1784400	0.0000012
EARTH	1970-12-30 17:18	< 1 min	0.1715731	0.1715690	0.0000014
EARTH	1972-04-01 13:26	< 1 min	0.1468486	0.1468464	0.0000007
EARTH	1981-04-02 15:55	< 1 s	0.1257052	0.1257045	0.0000002
EARTH	1990-04-02 05:15	< 1 min	0.1265683	0.1265680	0.0000001
EARTH	1994-01-17 14:26	< 1 min	0.1806756	0.1806751	0.0000002
EARTH	1999-03-25 21:32	< 1 min	0.1629115	0.1629112	0.0000001
EARTH	2003-01-04 18:35	< 1 s	0.1225553	0.1225551	0.0000001
EARTH	2011-12-28 17:28	< 1 s	0.0570255	0.0570254	0.0000000
EARTH	2020-12-30 21:10	< 1 s	0.1843300	0.1843296	0.0000001
EARTH	2022-04-03 09:58	< 1 s	0.1318330	0.1318327	0.0000001
EARTH	2026-01-22 11:28	< 1 min	0.1973063	0.1973060	0.0000001
EARTH	2031-03-21 17:51	< 1 min	0.1793315	0.1793309	0.0000002
EARTH	2034-12-29 20:17	< 1 min	0.0717931	0.0717921	0.0000003
EARTH	2043-12-31 11:59	< 1 min	0.1771535	0.1771504	0.0000010
EARTH	2045-04-03 08:38	< 1 min	0.1329416	0.1329404	0.0000004
EARTH	2049-01-21 09:34	< 1 min	0.1947998	0.1947981	0.0000006
EARTH	2054-03-19 11:42	< 1 min	0.1859423	0.1859401	0.0000007
EARTH	2057-12-29 05:21	< 1 min	0.0643578	0.0643552	0.0000009
EARTH	2066-12-31 11:57	< 1 min	0.1786356	0.1786274	0.0000027
EARTH	2068-04-03 05:01	< 1 min	0.1337689	0.1337657	0.0000011
EARTH	2072-01-24 03:09	< 1 min	0.1996691	0.1996655	0.0000012
EARTH	2077-03-24 22:06	< 1 min	0.1687958	0.1687908	0.0000017
EARTH	2081-01-01 10:04	< 1 min	0.0988868	0.0988794	0.0000025
EARTH	2089-12-28 21:08	< 1 min	0.0752602	0.0752542	0.0000020
EARTH	2099-01-01 05:47	< 1 min	0.1887692	0.1887643	0.0000016
EARTH	2100-04-04 08:36	< 1 min	0.1349966	0.1349950	0.0000005
EARTH	2109-04-03 19:58	< 1 s	0.1303232	0.1303229	0.0000001
EARTH	2113-01-17 22:31	< 1 min	0.1759838	0.1759827	0.0000003
EARTH	2118-03-28 02:05	< 1 min	0.1626597	0.1626575	0.0000007
EARTH	2122-01-08 18:47	< 1 min	0.1347108	0.1347070	0.0000013

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
111.12879668	354.38493409	0.05640999	MINIMUM
247.60101997	90.30538619	0.12326453	MINIMUM
182.64503320	44.30073328	0.23343719	SADDLE
358.87738790	222.59411627	0.47330272	SADDLE
357.80947567	40.93720869	1.52742505	SADDLE
178.39179529	221.49474776	2.22518486	MAXIMUM

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MOID Plots

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