Asteroids

162181 1999LF6 help

Last update: 2025-09-10 00:30 UTC

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Apollo

Perihelion (q)

1.014

Aphelion (Q)

1.805

Eccentricity (e)

0.281

Inclination (i)

18.9

deg

Orbit period (P)

611.3

Earth MOID

0.06391

U parameter

0.0

A₂

-14.9

10^-15au/days²

Next Earth close approach

Date

2081-10-12

Nominal distance (from Earth center)

0.13728

20537085

Maximum Brightness

16.2

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

18.2

mag

Diameter

856

Taxonomic type

S/Sr

Rotation period (T)

37.40

Discovery Information

Discovery Date

1999-06-10

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

1.409600

1-sigma variation

2.752E-9

Unit

Eccentricity (e)

Value

0.280592

1-sigma variation

8.864E-9

Unit

Inclination (i)

Value

18.9433

1-sigma variation

3.136E-6

Unit

Long. of Ascending Node (Ω)

Value

208.4935

1-sigma variation

2.394E-6

Unit

Arg. of Perihelion (ω)

Value

140.8751

1-sigma variation

5.947E-6

Unit

Mean Anomaly (M)

Value

237.23719

1-sigma variation

0.00001

Unit

Perihelion distance

Value

1.014078

1-sigma variation

Unit

Aphelion distance

Value

1.805122

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.654218

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.071024

1-sigma variation

Unit

MOID

Value

0.063905

1-sigma variation

Unit

Orbit Period

Value

611.2828

1-sigma variation

Unit

U parameter

Value

0.0

1-sigma variation

Unit

A₂

Value

-14.91265

1-sigma variation

4.19027

Unit

10^-15au/days²

Covariance Matrix

	a	e	i	Ω	ω	M	A₂
a	7.57251E-18	-1.73926E-17	2.89096E-15	-3.80905E-16	6.89565E-15	-1.83401E-14	1.12483E-8
e	-1.73926E-17	7.85649E-17	-6.69087E-15	2.63873E-15	-3.54650E-14	5.66326E-14	-2.30705E-8
i	2.89096E-15	-6.69087E-15	9.83333E-12	-2.49057E-12	5.23785E-12	-8.50802E-12	4.05312E-6
Ω	-3.80905E-16	2.63873E-15	-2.49057E-12	5.73309E-12	-1.03541E-11	6.35204E-12	7.22039E-9
ω	6.89565E-15	-3.54650E-14	5.23785E-12	-1.03541E-11	3.53691E-11	-3.63428E-11	7.64956E-6
M	-1.83401E-14	5.66326E-14	-8.50802E-12	6.35204E-12	-3.63428E-11	6.17728E-11	-2.40172E-5
A₂	1.12483E-8	-2.30705E-8	4.05312E-6	7.22039E-9	7.64956E-6	-2.40172E-5	1.75584E1

Date of computation: 2025-09-10 00:30 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

14.77

37.40

Unit

Source

[4]

[1]

Quality

Value

Unit

Source

[4]

Amplitude

Value

0.17-0.23

0.33

Unit

mag

Source

[4]

[1]

Rotation Direction

Value

Unit

Source

[-]

Spinvector L

Value

229

Unit

Source

[1]

Spinvector B

Value

Unit

Source

[1]

Taxonomy
Taxonomy (all)

Taxonomy

Value

Unit

Source

Taxonomy

Value

S/Sr

Unit

Source

[2]

Taxonomy (all)

Value

L;S/Sr

Unit

Source

[3]

Absolute Magnitude (H)
Slope Parameter (G)

H / G

Value

Unit

Source

Absolute Magnitude (H)

Value

18.195

Unit

mag

Source

[5]

Slope Parameter (G)

Value

0.15**

Unit

mag

Source

[5]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.127

Unit

Source

[6]

Diameter

Value

856

Unit

Source

[6]

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

[7]

Download this part as:

Sources

No.	Name	Additional
[1]	EARN	1.) Near-Earth Asteroid Lightcurve Analysis at the Center for Solar System Studies: 2019 March-July, B.D. Warner
[2]	EARN	1.) DeMeo, F.E. et al. (2014) Icarus 227, 112-122. (Mars encounters cause fresh surfaces on some near-Earth asteroids) (contains taxonomic classification of 249 NEAs)
[3]	EARN	1.) Somers, J.M. et al. (2010) DPS 42, 1316. (abstract) (Optical Characterization Of Planetary Radar Targets, Low-deltaV, And Potentially Hazardous Asteroids: Results From 2009-2010) 2.) DeMeo, F.E. et al. (2014) Icarus 227, 112-122. (Mars encounters cause fresh surfaces on some near-Earth asteroids) (contains taxonomic classification of 249 NEAs)
[4]	EARN	1.) Warner, B.D. (2014) MPB 41, 213-224. (NEAR-EARTH ASTEROID LIGHTCURVE ANALYSIS AT CS3-PALMER DIVIDE STATION: 2014 MARCH-JUNE) (38 NEA lightcurve data) 2.) Petr Pravec's Ondrejov NEO Photometric Program Webpage "Prepublished Periods" 3.) Krugly, Yu. N. et al. (2006) IAU Symp. 236, 385-390. (Kharkiv study of near-Earth asteroids) (1036,1627,1685, 1862,1980,3103,3200,4179,6611,8567,11405,13553,23187,54509, 66251,100085,1999LF6,2004XP14,2005AB,2006CV69,2006BQ6)
[5]	ESA Aegis	ESA orbit determination and impact monitoring system
[6]	EARN	1.) Mainzer, A. et al. (2011) ApJ 743, 156. (NEOWISE Observations of Near-Earth Objects: Preliminary Results) (albedo and diameters of 428 NEOs) 2.) Nugent, C.R. et al. (2015) Astrophys. J. 814_117 (13pp) (NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos)(201 NEOs) 3.) Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; et al. (2011) Astrophys. J. 741, A90. See also Grav 2012b and Masiero 2012.
[7]	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

16459

Unit

Source

[1]

Unobserved

Value

279

Unit

Source

[1]

Normalized RMS of residuals

Value

0.490081

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

1979-12-20.6266

Unit

Source

[2]

Last Observation

Value

2025-01-11.141515

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

1906 (6)

Unit

Source

[1]

Radar Summary

First Observation
Last Observation
Delay (Discarded)
Doppler (Discarded)
Total Optical Observations (Discarded)

Radar

Value

Unit

Source

First Observation

Value

2004-10-18

Unit

Source

[3]

Last Observation

Value

2004-10-21

Unit

Source

[3]

Delay (Discarded)

Value

2 (0)

Unit

Source

[1]

Doppler (Discarded)

Value

0 (0)

Unit

Source

[-]

Total Radar Observations (Discarded)

Value

2 (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 162181 1999LF6 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	1994-10-10 22:57	< 1 s	0.1742679	0.1742676	0.0000001
EARTH	1999-10-15 14:00	< 1 s	0.0871762	0.0871761	0.0000000
EARTH	2004-10-18 12:02	< 1 s	0.0708964	0.0708964	0.0000000
EARTH	2009-10-23 00:53	< 1 s	0.1501531	0.1501530	0.0000000
EARTH	2081-10-12 13:40	< 1 min	0.1372819	0.1372753	0.0000022
EARTH	2086-10-17 00:18	< 1 min	0.0674785	0.0674757	0.0000009
EARTH	2091-10-21 00:37	< 1 min	0.0923694	0.0923611	0.0000028
EARTH	2096-10-24 18:04	< 1 min	0.1875553	0.1875416	0.0000045

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
26.20813317	282.76539950	0.06428570	MINIMUM
165.99508366	57.75133008	0.86825558	SADDLE
352.01870618	58.89315784	1.99361163	SADDLE
182.03140051	249.69782978	2.79751460	MAXIMUM

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MOID Plots

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