Asteroids

2011MD help

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

Orbital Properties

Epoch

61200.0

MJD

Orbit type

Amor

Perihelion (q)

1.017

Aphelion (Q)

1.097

Eccentricity (e)

0.038

Inclination (i)

2.4

deg

Orbit period (P)

397.0

Earth MOID

0.00102

U parameter

2.0

A₁

61459.5

10^-15au/days²

Next Earth close approach

Date

2036-05-23

Nominal distance (from Earth center)

0.11398

17051501

Maximum Brightness

26.2

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

mag

Diameter

Taxonomic type

Rotation period (T)

0.1937

Discovery Information

Discovery Date

2011-06-22

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

1.057088

1-sigma variation

8.189E-8

Unit

Eccentricity (e)

Value

0.037677

1-sigma variation

1.966E-8

Unit

Inclination (i)

Value

2.4426

1-sigma variation

1.966E-6

Unit

Long. of Ascending Node (Ω)

Value

271.3851

1-sigma variation

1.592E-5

Unit

Arg. of Perihelion (ω)

Value

5.7240

1-sigma variation

0.0001

Unit

Mean Anomaly (M)

Value

275.68340

1-sigma variation

0.00033

Unit

Perihelion distance

Value

1.017260

1-sigma variation

Unit

Aphelion distance

Value

1.096915

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.001032

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.112795

1-sigma variation

Unit

MOID

Value

0.001017

1-sigma variation

Unit

Orbit Period

Value

396.9768

1-sigma variation

Unit

U parameter

Value

2.0

1-sigma variation

Unit

A₁

Value

61459.49728

1-sigma variation

15745.29528

Unit

10^-15au/days²

Covariance Matrix

	a	e	i	Ω	ω	M	A₁
a	6.70590E-15	1.57336E-15	7.41893E-14	-2.33435E-13	-6.73602E-12	2.03943E-11	-1.27556E-3
e	1.57336E-15	3.86365E-16	2.34017E-14	7.78509E-15	-1.71186E-12	3.90483E-12	-3.08476E-4
i	7.41893E-14	2.34017E-14	3.86407E-12	2.19729E-11	-1.26382E-10	-9.33069E-11	-1.74831E-2
Ω	-2.33435E-13	7.78509E-15	2.19729E-11	2.53389E-10	-3.31558E-10	-4.07122E-9	8.67967E-3
ω	-6.73602E-12	-1.71186E-12	-1.26382E-10	-3.31558E-10	8.32855E-9	-1.27595E-8	1.36583E0
M	2.03943E-11	3.90483E-12	-9.33069E-11	-4.07122E-9	-1.27595E-8	1.08857E-7	-3.38296E0
A₁	-1.27556E-3	-3.08476E-4	-1.74831E-2	8.67967E-3	1.36583E0	-3.38296E0	2.47914E8

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

0.1937

Unit

Source

[1]

Quality

Value

Unit

Source

[1]

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

27.957

Unit

mag

Source

[2]

Slope Parameter (G)

Value

0.15**

Unit

Source

[2]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.3

Unit

Source

[3]

Diameter

Value

Unit

Source

[3]

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]	EARN	1.) Skiff, B.A. (2011) Posting on CALL web site. http://www.minorplanet.info/call.html
[2]	ESA Aegis	ESA orbit determination and impact monitoring system
[3]	EARN	1.) Mommert, M. et al. (2014) Astrophys. J. 789, L22. (PHYSICAL PROPERTIES OF NEAR-EARTH ASTEROID 2011 MD)

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

967

Unit

Source

[1]

Unobserved

Value

4514

Unit

Source

[1]

Normalized RMS of residuals

Value

0.431733

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2011-06-21.28286

Unit

Source

[2]

Last Observation

Value

2014-02-12.264621

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

1560 (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):

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Plot

Computation parameters

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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 2011MD 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	1962-06-24 04:27	9.8	0.0912437	0.0905829	0.0002203
EARTH	1963-01-11 10:57	442.8	0.0595597	0.0594363	0.0000417
EARTH	1963-09-17 22:20	3.5	0.1676272	0.1669708	0.0002188
EARTH	1985-06-24 11:55	< 1 min	0.0563993	0.0563599	0.0000131
EARTH	1985-12-29 10:07	24.1	0.0496188	0.0496121	0.0000022
EARTH	1986-09-20 01:55	< 1 min	0.1660665	0.1660281	0.0000128
EARTH	2011-06-27 16:59	< 1 s	0.0001247	0.0001247	0.0000000
EARTH	2024-02-04 14:01	11.4	0.1062822	0.1062798	0.0000008
EARTH	2024-08-10 04:56	< 1 min	0.1503369	0.1503204	0.0000055
EARTH	2036-05-23 09:25	< 1 min	0.1139822	0.1139697	0.0000042
EARTH	2036-11-11 17:16	8.7	0.0977463	0.0977437	0.0000009
EARTH	2049-06-12 19:55	3.8	0.0138573	0.0138394	0.0000060
EARTH	2049-10-01 04:31	36.5	0.0597004	0.0596881	0.0000041
EARTH	2067-05-24 08:43	36.2	0.1333074	0.1300473	0.0010869
EARTH	2067-12-20 08:19	> 1 d	0.0744281	0.0741550	0.0000999
EARTH	2068-08-18 06:22	20.7	0.1931887	0.1902404	0.0009830
EARTH	2086-06-13 01:18	485.6	0.0061363	0.0025958	0.0012326
EARTH	2086-12-21 14:08	> 1 d	0.0354444	0.0223836	0.0173666
EARTH	2087-05-28 03:42	> 1 w	0.0232248	0.0165311	0.0227256

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
354.54360970	169.87769386	0.00051353	MINIMUM
184.04626519	359.61046876	0.11351470	SADDLE
1.42872917	357.14624437	2.00078109	SADDLE
181.16943408	176.88677359	2.11505207	MAXIMUM

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MOID Plots

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