Asteroids

2011UH20 help

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

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Apollo

Perihelion (q)

0.817

Aphelion (Q)

1.645

Eccentricity (e)

0.336

Inclination (i)

35.8

deg

Orbit period (P)

498.8

Earth MOID

0.01089

U parameter

0.0

Next Earth close approach

Date

2033-04-08

Nominal distance (from Earth center)

0.08348

12488735

Maximum Brightness

18.7

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

mag

Diameter

170 - 400*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2011-10-18

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

1.230927

1-sigma variation

4.444E-9

Unit

Eccentricity (e)

Value

0.336084

1-sigma variation

8.036E-8

Unit

Inclination (i)

Value

35.7706

1-sigma variation

1.604E-5

Unit

Long. of Ascending Node (Ω)

Value

21.6005

1-sigma variation

8.027E-6

Unit

Arg. of Perihelion (ω)

Value

257.1692

1-sigma variation

1.815E-5

Unit

Mean Anomaly (M)

Value

173.75953

1-sigma variation

0.00002

Unit

Perihelion distance

Value

0.817233

1-sigma variation

Unit

Aphelion distance

Value

1.644621

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.182464

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.012419

1-sigma variation

Unit

MOID

Value

0.010889

1-sigma variation

Unit

Orbit Period

Value

498.8233

1-sigma variation

Unit

U parameter

Value

0.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	1.97511E-17	-1.89243E-16	2.13761E-16	-7.33003E-15	2.74343E-14	-8.50910E-14
e	-1.89243E-16	6.45768E-15	7.81798E-14	5.71406E-14	-2.74997E-13	4.05375E-13
i	2.13761E-16	7.81798E-14	2.57320E-10	-3.20825E-11	-1.06282E-12	8.67378E-12
Ω	-7.33003E-15	5.71406E-14	-3.20825E-11	6.44390E-11	-1.44261E-11	3.63074E-12
ω	2.74343E-14	-2.74997E-13	-1.06282E-12	-1.44261E-11	3.29327E-10	-3.46286E-10
M	-8.50910E-14	4.05375E-13	8.67378E-12	3.63074E-12	-3.46286E-10	6.17035E-10

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

21.032

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

170 - 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

[-]

Download this part as:

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

4007

Unit

Source

[1]

Unobserved

Value

1152

Unit

Source

[1]

Normalized RMS of residuals

Value

0.6025

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2011-10-18.15098

Unit

Source

[2]

Last Observation

Value

2022-10-07.385227

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

96 (1)

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

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 2011UH20 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	1962-04-07 21:02	1.4	0.1098162	0.1097417	0.0000248
EARTH	1977-04-11 23:31	< 1 min	0.0117337	0.0117334	0.0000001
EARTH	1981-10-07 05:12	< 1 s	0.1967992	0.1967976	0.0000005
EARTH	1992-04-15 21:43	< 1 min	0.1104820	0.1104794	0.0000009
EARTH	1996-10-07 23:03	< 1 min	0.1531036	0.1531033	0.0000001
EARTH	2011-10-10 20:46	< 1 s	0.1835063	0.1835060	0.0000001
EARTH	2033-04-08 20:41	< 1 min	0.0834820	0.0834803	0.0000006
EARTH	2048-04-12 15:10	< 1 min	0.0229115	0.0229094	0.0000007
EARTH	2052-10-07 08:21	< 1 s	0.1744088	0.1744081	0.0000002
EARTH	2067-10-10 23:06	< 1 min	0.1822528	0.1822502	0.0000009
EARTH	2074-04-05 04:53	< 1 min	0.1828215	0.1828142	0.0000024
EARTH	2089-04-12 21:52	< 1 min	0.0216322	0.0216226	0.0000032
EARTH	2093-10-07 21:30	< 1 min	0.1639205	0.1639181	0.0000008
EARTH	2115-04-13 05:04	< 1 min	0.0196980	0.0196858	0.0000041
EARTH	2119-10-09 00:50	< 1 min	0.1950905	0.1950819	0.0000029

Download as:

Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
301.78555327	98.90347229	0.01189087	MINIMUM
75.17471166	273.85867059	0.15166382	MINIMUM
8.92342530	189.34605825	0.59404456	SADDLE
188.94469360	1.32461107	1.01497710	SADDLE
4.49130833	1.44531684	1.71693831	SADDLE
172.36432230	167.43177411	2.54904145	MAXIMUM

Download:

MOID Plots

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