Asteroids

444004 2004AS1 help

Last update: 2026-06-04 23:11 UTC

Orbital Properties

Epoch

61200.0

MJD

Orbit type

Apollo

Perihelion (q)

0.884

Aphelion (Q)

1.257

Eccentricity (e)

0.174

Inclination (i)

17.2

deg

Orbit period (P)

404.5

Earth MOID

0.02254

U parameter

0.0

Next Earth close approach

Date

2035-02-16

Nominal distance (from Earth center)

0.14021

20975073

Maximum Brightness

18.8

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

20.6

mag

Diameter

210 - 500*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2004-01-13

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

61200.0000

1-sigma variation

Unit

MJD

Semimajor Axis

Value

1.070367

1-sigma variation

1.248E-9

Unit

Eccentricity (e)

Value

0.174354

1-sigma variation

4.575E-8

Unit

Inclination (i)

Value

17.2164

1-sigma variation

7.974E-6

Unit

Long. of Ascending Node (Ω)

Value

322.5028

1-sigma variation

5.835E-6

Unit

Arg. of Perihelion (ω)

Value

262.0279

1-sigma variation

1.283E-5

Unit

Mean Anomaly (M)

Value

348.87972

1-sigma variation

0.00002

Unit

Perihelion distance

Value

0.883744

1-sigma variation

Unit

Aphelion distance

Value

1.256990

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.050360

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.026374

1-sigma variation

Unit

MOID

Value

0.022545

1-sigma variation

Unit

Orbit Period

Value

404.4803

1-sigma variation

Unit

U parameter

Value

0.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	1.55653E-18	4.72716E-17	2.95752E-16	2.53611E-16	2.59200E-15	-9.35362E-15
e	4.72716E-17	2.09343E-15	4.98544E-14	3.30355E-15	1.47871E-13	-4.12757E-13
i	2.95752E-16	4.98544E-14	6.35894E-11	6.84052E-12	-1.25541E-11	7.22117E-12
Ω	2.53611E-16	3.30355E-15	6.84052E-12	3.40505E-11	-3.37998E-11	2.00228E-12
ω	2.59200E-15	1.47871E-13	-1.25541E-11	-3.37998E-11	1.64710E-10	-1.73413E-10
M	-9.35362E-15	-4.12757E-13	7.22117E-12	2.00228E-12	-1.73413E-10	2.61740E-10

Date of computation: 2026-06-04 23:11 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

20.56

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

210 - 500*

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

8011

Unit

Source

[1]

Unobserved

Value

192

Unit

Source

[1]

Normalized RMS of residuals

Value

0.488059

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2004-01-13.33056

Unit

Source

[2]

Last Observation

Value

2025-12-19.146554

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

329 (0)

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:

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Time step:*

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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 444004 2004AS1 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	1952-02-12 07:18	< 1 s	0.0631285	0.0631278	0.0000002
EARTH	1953-08-13 14:07	< 1 s	0.1337392	0.1337389	0.0000001
EARTH	1963-08-11 09:22	< 1 s	0.1047616	0.1047613	0.0000001
EARTH	1973-02-15 18:05	< 1 s	0.1256981	0.1256979	0.0000001
EARTH	1983-02-10 09:45	< 1 s	0.1153436	0.1153431	0.0000001
EARTH	1984-08-12 03:30	< 1 s	0.0847366	0.0847358	0.0000003
EARTH	1994-08-12 08:50	< 1 s	0.1526570	0.1526562	0.0000003
EARTH	2004-02-16 00:02	< 1 s	0.0853949	0.0853946	0.0000001
EARTH	2014-02-09 19:53	< 1 s	0.1285778	0.1285774	0.0000001
EARTH	2015-08-12 17:42	< 1 s	0.0780984	0.0780981	0.0000001
EARTH	2025-08-11 08:13	< 1 s	0.1286026	0.1286023	0.0000001
EARTH	2035-02-16 07:54	< 1 s	0.1402097	0.1402088	0.0000003
EARTH	2045-02-11 21:18	< 1 s	0.0628272	0.0628262	0.0000003
EARTH	2046-08-14 05:07	< 1 s	0.1352884	0.1352880	0.0000001
EARTH	2056-08-10 17:50	< 1 s	0.1027009	0.1027005	0.0000001
EARTH	2066-02-16 01:32	< 1 s	0.1267877	0.1267871	0.0000002
EARTH	2076-02-11 00:39	< 1 min	0.1137277	0.1137266	0.0000004
EARTH	2077-08-12 16:54	< 1 s	0.0863493	0.0863478	0.0000005
EARTH	2087-08-12 11:10	< 1 s	0.1490337	0.1490325	0.0000004
EARTH	2097-02-15 10:36	< 1 s	0.0904287	0.0904284	0.0000001
EARTH	2107-02-11 14:12	< 1 s	0.1230492	0.1230485	0.0000002
EARTH	2108-08-13 09:04	< 1 s	0.0821500	0.0821498	0.0000001
EARTH	2118-08-12 14:40	< 1 s	0.1235873	0.1235867	0.0000002

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
289.91185562	42.64008064	0.02180283	MINIMUM
83.64807842	217.72833188	0.04179114	MINIMUM
7.11617637	130.84033957	0.31057254	SADDLE
186.54230054	309.23524839	0.42652836	SADDLE
5.51943279	308.84226517	1.85327518	SADDLE
182.41569726	125.65743014	2.24265052	MAXIMUM

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MOID Plots

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