Asteroids

481817 2008UL90 help

Last update: 2025-11-24 16:53 UTC

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Atira

Perihelion (q)

0.431

Aphelion (Q)

0.959

Eccentricity (e)

0.380

Inclination (i)

24.3

deg

Orbit period (P)

211.6

Earth MOID

0.02659

U parameter

0.8

Next Earth close approach

Date

2027-12-12

Nominal distance (from Earth center)

0.08094

12108008

Maximum Brightness

17.2

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

18.5

mag

Diameter

500 - 1200*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2008-10-26

Observatory

Mt. Lemmon Survey

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

0.695016

1-sigma variation

3.761E-9

Unit

Eccentricity (e)

Value

0.379899

1-sigma variation

3.526E-8

Unit

Inclination (i)

Value

24.3106

1-sigma variation

3.559E-6

Unit

Long. of Ascending Node (Ω)

Value

81.1216

1-sigma variation

3.233E-6

Unit

Arg. of Perihelion (ω)

Value

183.6633

1-sigma variation

2.762E-5

Unit

Mean Anomaly (M)

Value

322.83871

1-sigma variation

0.00006

Unit

Perihelion distance

Value

0.430980

1-sigma variation

Unit

Aphelion distance

Value

0.959053

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

-0.026724

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

-0.585838

1-sigma variation

Unit

MOID

Value

0.026586

1-sigma variation

Unit

Orbit Period

Value

211.6368

1-sigma variation

Unit

U parameter

Value

0.8

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	1.41464E-17	-3.15242E-17	1.59818E-15	1.57072E-15	-1.55474E-14	-1.47726E-13
e	-3.15242E-17	1.24305E-15	-4.71476E-14	1.43554E-14	2.86836E-13	-3.24931E-13
i	1.59818E-15	-4.71476E-14	1.26656E-11	7.38603E-12	-5.99208E-11	8.84908E-11
Ω	1.57072E-15	1.43554E-14	7.38603E-12	1.04517E-11	-7.82027E-11	1.13516E-10
ω	-1.55474E-14	2.86836E-13	-5.99208E-11	-7.82027E-11	7.63080E-10	-1.19654E-9
M	-1.47726E-13	-3.24931E-13	8.84908E-11	1.13516E-10	-1.19654E-9	4.05650E-9

Date of computation: 2025-11-24 16:53 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

18.53

Unit

mag

Source

[1]

Slope Parameter (G)

Value

0.15**

Unit

mag

Source

[1]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.05 - 0.25

Unit

Source

[2]

Diameter

Value

500 - 1200*

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

Radar R

Unit

Source

[3]

Download this part as:

Sources

No.	Name	Additional
[1]	ESA Aegis	ESA orbit determination and impact monitoring system
[2]	Estimation	Estimated from absolute magnitude
[3]	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

5537

Unit

Source

[1]

Unobserved

Value

707

Unit

Source

[1]

Normalized RMS of residuals

Value

0.533157

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2008-10-26.48633

Unit

Source

[2]

Last Observation

Value

2023-12-24.634742

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

337 (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

2016-12-15

Unit

Source

[3]

Last Observation

Value

2016-12-20

Unit

Source

[3]

Delay (Discarded)

Value

4 (0)

Unit

Source

[1]

Doppler (Discarded)

Value

3 (0)

Unit

Source

[1]

Total Radar Observations (Discarded)

Value

7 (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 481817 2008UL90 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
MERCURY	1953-07-11 16:20	1.5	0.0457689	0.0457537	0.0000050
EARTH	1954-12-12 02:02	< 1 min	0.0766330	0.0766154	0.0000059
MERCURY	1956-06-07 04:02	1.3	0.0285843	0.0285787	0.0000019
EARTH	1961-12-17 03:53	< 1 min	0.1595886	0.1595694	0.0000064
EARTH	1965-12-11 03:48	< 1 min	0.1332368	0.1332174	0.0000065
MERCURY	1972-01-27 21:14	1.5	0.0425943	0.0425795	0.0000049
EARTH	1972-12-15 18:05	< 1 min	0.1019610	0.1019437	0.0000058
MERCURY	1974-12-24 08:43	1.2	0.0304799	0.0304710	0.0000030
EARTH	1976-12-10 19:22	< 1 min	0.1915646	0.1915475	0.0000057
EARTH	1983-12-15 04:27	< 1 min	0.0530059	0.0529941	0.0000039
MERCURY	1993-07-07 21:45	< 1 min	0.0313400	0.0313370	0.0000010
EARTH	1994-12-14 01:31	< 1 min	0.0291300	0.0291278	0.0000007
MERCURY	1996-06-01 22:45	< 1 min	0.0379015	0.0378971	0.0000014
EARTH	2005-12-13 10:04	< 1 min	0.0267678	0.0267676	0.0000001
EARTH	2016-12-12 14:52	< 1 s	0.0391436	0.0391436	0.0000000
MERCURY	2017-11-04 07:58	< 1 min	0.0298366	0.0298363	0.0000001
MERCURY	2020-09-30 01:38	< 1 min	0.0483420	0.0483408	0.0000004
EARTH	2027-12-12 11:56	< 1 s	0.0809370	0.0809357	0.0000005
EARTH	2034-12-17 14:37	< 1 min	0.1545015	0.1544994	0.0000007
MERCURY	2036-05-21 04:27	< 1 min	0.0319028	0.0319017	0.0000004
EARTH	2038-12-11 16:01	< 1 s	0.1380695	0.1380670	0.0000008
MERCURY	2039-04-17 05:40	< 1 min	0.0444051	0.0444024	0.0000009
EARTH	2045-12-16 02:59	< 1 min	0.0974314	0.0974286	0.0000009
EARTH	2049-12-11 09:53	< 1 s	0.1969392	0.1969361	0.0000010
MERCURY	2054-12-06 18:27	< 1 min	0.0320447	0.0320431	0.0000005
EARTH	2056-12-14 13:25	< 1 min	0.0502915	0.0502888	0.0000009
MERCURY	2057-11-01 13:05	< 1 min	0.0419084	0.0419053	0.0000010
EARTH	2067-12-14 11:41	< 1 min	0.0286147	0.0286138	0.0000003
MERCURY	2076-05-11 09:26	< 1 min	0.0432388	0.0432356	0.0000011
EARTH	2078-12-13 20:52	< 1 min	0.0270355	0.0270347	0.0000003
MERCURY	2079-04-06 13:56	< 1 min	0.0293810	0.0293809	0.0000000
EARTH	2089-12-13 01:11	< 1 min	0.0404931	0.0404826	0.0000035
MERCURY	2097-10-16 15:11	1.6	0.0475552	0.0475400	0.0000051
MERCURY	2100-09-13 01:14	1.5	0.0293177	0.0293156	0.0000007
EARTH	2100-12-12 22:33	< 1 min	0.0837906	0.0837708	0.0000066
EARTH	2107-12-19 02:41	< 1 min	0.1524300	0.1524076	0.0000075
EARTH	2111-12-13 04:15	< 1 min	0.1417041	0.1416804	0.0000079
MERCURY	2116-05-04 12:22	1.9	0.0460228	0.0460045	0.0000061
EARTH	2118-12-17 13:35	< 1 min	0.0957440	0.0957222	0.0000072
MERCURY	2119-04-01 09:56	1.6	0.0306742	0.0306659	0.0000028
EARTH	2122-12-13 00:10	< 1 min	0.1992727	0.1992501	0.0000075

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
175.07046394	339.55530217	0.02671606	MINIMUM
20.60217166	190.88340321	0.58930567	SADDLE
3.69069389	346.76867590	1.41492159	SADDLE
179.89854992	162.46884290	1.97441656	MAXIMUM

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MOID Plots

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