Asteroids

101869 1999MM help

Last update: 2025-07-29 02:36 UTC

Orbital Properties

Epoch

60800.0

MJD

Orbit type

Apollo

Perihelion (q)

0.632

Aphelion (Q)

2.616

Eccentricity (e)

0.611

Inclination (i)

4.8

deg

Orbit period (P)

756.0

Earth MOID

0.00135

U parameter

0.0

Next Earth close approach

Date

2030-07-29

Nominal distance (from Earth center)

0.19309

28885230

Maximum Brightness

19.5

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

19.5

mag

Diameter

300 - 800*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

1999-06-20

Observatory

Lowell Observatory-LONEOS

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

60800.0000

1-sigma variation

Unit

MJD

Semimajor Axis

Value

1.624100

1-sigma variation

3.483E-9

Unit

Eccentricity (e)

Value

0.610829

1-sigma variation

5.414E-8

Unit

Inclination (i)

Value

4.7654

1-sigma variation

1.309E-5

Unit

Long. of Ascending Node (Ω)

Value

110.9228

1-sigma variation

4.500E-5

Unit

Arg. of Perihelion (ω)

Value

268.8380

1-sigma variation

4.477E-5

Unit

Mean Anomaly (M)

Value

147.93728

1-sigma variation

0.00002

Unit

Perihelion distance

Value

0.632053

1-sigma variation

Unit

Aphelion distance

Value

2.616147

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.046477

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

-0.009867

1-sigma variation

Unit

MOID

Value

0.001351

1-sigma variation

Unit

Orbit Period

Value

755.9927

1-sigma variation

Unit

U parameter

Value

0.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	1.21341E-17	1.54085E-16	-3.44847E-15	-6.31304E-15	8.03638E-15	-6.88221E-14
e	1.54085E-16	2.93153E-15	-3.03006E-14	-1.81620E-13	1.75795E-13	-8.83056E-13
i	-3.44847E-15	-3.03006E-14	1.71376E-10	-1.35451E-10	1.38563E-10	1.06734E-11
Ω	-6.31304E-15	-1.81620E-13	-1.35451E-10	2.02474E-9	-1.97335E-9	6.90508E-12
ω	8.03638E-15	1.75795E-13	1.38563E-10	-1.97335E-9	2.00399E-9	-7.82120E-11
M	-6.88221E-14	-8.83056E-13	1.06734E-11	6.90508E-12	-7.82120E-11	4.89728E-10

Date of computation: 2025-07-29 02:36 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

19.469

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

300 - 800*

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

7238

Unit

Source

[1]

Unobserved

Value

2332

Unit

Source

[1]

Normalized RMS of residuals

Value

0.697354

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

1999-06-12.30263

Unit

Source

[2]

Last Observation

Value

2019-04-06.53921

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

207 (2)

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 101869 1999MM 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	1970-07-24 19:31	< 1 s	0.1630587	0.1630581	0.0000002
EARTH	1977-01-10 04:35	< 1 min	0.0659769	0.0659742	0.0000009
EARTH	1999-07-07 15:01	< 1 s	0.0882120	0.0882117	0.0000001
EARTH	2005-12-27 08:48	< 1 min	0.1480236	0.1480230	0.0000002
EARTH	2030-07-29 10:52	< 1 min	0.1930858	0.1930832	0.0000009
EARTH	2037-01-16 09:15	< 1 min	0.1787533	0.1787517	0.0000005
EARTH	2059-07-22 20:49	< 1 min	0.1341601	0.1341594	0.0000002
EARTH	2066-01-14 04:30	< 1 min	0.1236796	0.1236776	0.0000007
VENUS	2074-03-29 21:05	< 1 min	0.0354842	0.0354837	0.0000002
EARTH	2088-07-14 01:58	< 1 min	0.0244582	0.0244534	0.0000016
VENUS	2090-09-09 01:04	< 1 min	0.0052690	0.0052682	0.0000003
MARS	2091-01-29 16:09	< 1 min	0.0363685	0.0363675	0.0000003
EARTH	2094-12-22 23:01	2.5	0.1918820	0.1918411	0.0000136
EARTH	2097-01-15 16:28	1.5	0.1494230	0.1493582	0.0000216
VENUS	2115-06-20 14:02	5.6	0.0340753	0.0340663	0.0000031
EARTH	2125-07-20 21:56	12.2	0.0982276	0.0978915	0.0001121

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
307.80704180	187.85533973	0.00135053	MINIMUM
49.85721190	4.26813723	0.00620130	MINIMUM
358.17492979	275.27416272	0.37186915	SADDLE
179.54817518	96.94322540	1.61984508	SADDLE
358.10558882	95.13731819	1.63236047	SADDLE
179.53643381	276.93883672	3.61143950	MAXIMUM

Download:

MOID Plots

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