Asteroids

308635 2005YU55 help

Last update: 2026-07-30 09:40 UTC

Orbital Properties

Epoch

61200.0

MJD

Orbit type

Apollo

Perihelion (q)

0.659

Aphelion (Q)

1.655

Eccentricity (e)

0.431

Inclination (i)

0.3

deg

Orbit period (P)

454.4

Earth MOID

0.00043

U parameter

0.0

Next Earth close approach

Date

2036-10-31

Nominal distance (from Earth center)

0.12147

18171452

Maximum Brightness

20.1

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

21.7

mag

Diameter

306

Taxonomic type

Rotation period (T)

19.31

Discovery Information

Discovery Date

2005-12-28

Observatory

Steward Observatory, Kitt Peak-Spacewatch

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

1.156791

1-sigma variation

2.136E-9

Unit

Eccentricity (e)

Value

0.430588

1-sigma variation

1.497E-9

Unit

Inclination (i)

Value

0.3398

1-sigma variation

1.087E-6

Unit

Long. of Ascending Node (Ω)

Value

35.9227

1-sigma variation

3.498E-5

Unit

Arg. of Perihelion (ω)

Value

273.5770

1-sigma variation

3.497E-5

Unit

Mean Anomaly (M)

Value

304.61407

1-sigma variation

0.00002

Unit

Perihelion distance

Value

0.658691

1-sigma variation

Unit

Aphelion distance

Value

1.654891

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

-0.080262

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

-0.033123

1-sigma variation

Unit

MOID

Value

0.000430

1-sigma variation

Unit

Orbit Period

Value

454.4444

1-sigma variation

Unit

U parameter

Value

0.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	4.56282E-18	3.38314E-19	-7.31283E-17	4.23401E-15	-3.63896E-15	-3.21442E-14
e	3.38314E-19	2.24058E-18	5.50268E-17	-2.91240E-15	2.75764E-15	-2.49235E-15
i	-7.31283E-17	5.50268E-17	1.18061E-12	3.63470E-11	-3.63635E-11	4.96348E-13
Ω	4.23401E-15	-2.91240E-15	3.63470E-11	1.22335E-9	-1.22303E-9	-3.06462E-11
ω	-3.63896E-15	2.75764E-15	-3.63635E-11	-1.22303E-9	1.22281E-9	2.64654E-11
M	-3.21442E-14	-2.49235E-15	4.96348E-13	-3.06462E-11	2.64654E-11	2.26459E-10

Date of computation: 2026-07-30 09:40 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

19.31

Unit

Source

[4]

Quality

Value

Unit

Source

[4]

Amplitude

Value

0.2

Unit

mag

Source

[4]

Rotation Direction

Value

RETRO

Unit

Source

[1]

Spinvector L

Value

Unit

Source

[1]

Spinvector B

Value

-60

Unit

Source

[1]

Taxonomy
Taxonomy (all)

Taxonomy

Value

Unit

Source

Taxonomy

Value

Unit

Source

[2]

Taxonomy (all)

Value

Unit

Source

[3]

Absolute Magnitude (H)
Slope Parameter (G)

H / G

Value

Unit

Source

Absolute Magnitude (H)

Value

21.27

21.671

Unit

mag

Source

[5]

[6]

Slope Parameter (G)

Value

0.15**

-0.147

Unit

Source

[6]

[5]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.065

Unit

Source

[8]

Diameter

Value

306

Unit

Source

[7]

Color Index Information

Color Index Information

Value

Unit

Source

Color Index Information

Value

0.34

0.67

Unit

V-R

B-V

Source

[9]

Sightings

Sightings

Value

Unit

Source

Sightings

Value

Visual S

Radar R

Unit

Source

[10]

[11]

Download this part as:

Sources

No.	Name	Additional
[1]	EARN	1.) Mueller, T.G. et al. (2013) Astron. Astrophys. 558, A97. (Physical Properties of Asteroid (308635) 2005 YU55 derived from multi-instrument infrared observations during a very close Earth-Approach) 2.) Merline, W.J. et al. (2011) I.A.U. Circ. HREF="http://www.cbat.eps.harvard.edu/iauc/09200/09242.html"> 9242. (2005 YU_55) (NIR/AO-observations with Keck II)
[2]	EARN	1.) Hicks, M. et al. (2010) href="http://www.astronomerstelegram.org/?read=2571"> ATel#2571 (Palomar Spectroscopy of 2001 FM129, 2004 FG11, and 2005 YU55)
[3]	EARN	1.) Hicks, M. et al. (2010) href="http://www.astronomerstelegram.org/?read=2571"> ATel#2571 (Palomar Spectroscopy of 2001 FM129, 2004 FG11, and 2005 YU55) 2.) 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)
[4]	EARN	1.) Warner, B.D. et al. (2012) ACM2012, 6013. (CCD PHOTOMETRIC OBSERVATIONS OF 2005 YU55 DURING THE 2011 NOVEMBER FLYBY) 2.) Warner, B.D. et al. (2001) href="http://www.minorplanet.info/ObsGuides/YU55/">2005 YU55 Observing Campaign Webpage 3.) Gyorgyey Ries, J. (2012) AAS 219, 432.13 (Broadband CCD Photometry of 2005 YU55 in Four Colors at McDonald Observatory) (November 2011 flyby)
[5]	EARN	1.) Warner, B.D. et al. (2012) ACM2012, 6013. (CCD PHOTOMETRIC OBSERVATIONS OF 2005 YU55 DURING THE 2011 NOVEMBER FLYBY) 2.) Hicks, M. et al. (2011) href="http://www.astronomerstelegram.org/?read=3763"> ATel#3763 (Broadband photometry of 2005 YU55: Solar phase behavior and absolute magnitude) 3.) Bodewits, D. et al. (2011) CBET HREF="http://www.cbat.eps.harvard.edu/iau/cbet/002900/CBET002937.txt"> 2937. (2005 YU_55)) (UV observations)
[6]	ESA Aegis	ESA orbit determination and impact monitoring system
[7]	EARN	1.) Mueller, T.G. et al. (2013) Astron. Astrophys. 558, A97. (Physical properties of asteroid 308635 (2005 YU55) derived from multi-instrument infrared observations during a very close Earth approach) 2.) Merline, W.J. et al. (2011) I.A.U. Circ. HREF="http://www.cbat.eps.harvard.edu/iauc/09200/09242.html"> 9242. (2005 YU_55) (NIR/AO-observations with Keck II) 3.) Mueller, T. et al. (2011) I.A.U. Circ. HREF="http://www.cbat.eps.harvard.edu/iauc/09200/09241.html"> 9241. (2005 YU_55) (IR-observation with Herschel) 4.) Hicks, M. et al. (2011) href="http://www.astronomerstelegram.org/?read=3763"> ATel#3763 (Broadband photometry of 2005 YU55: Solar phase behavior and absolute magnitude) 5.) Busch, M.W. et al. (2012) ACM2012, 6179. (Shape and Spin of Near-Earth Asteroid 308635 (2005 YU55) From Radar Images and Speckle Tracking) 6.) Mueller, T.G. et al. (2013) Astron. Astrophys. 558, A97. (Physical Properties of Asteroid (308635) 2005 YU55 derived from multi-instrument infrared observations during a very close Earth-Approach) 7.) Mueller, T.G. et al. (2011) Astron. Astrophys 525, A145. (Thermo-physical properties of 162173 (1999 JU3), a potential flyby and rendezvous target for interplanetary missions) 8.) Moskovitz, N.A. et al. (2012) ACM2012, 6382. (THE NEAR-EARTH ENCOUNTER OF 2005 YU55: TIME-RESOLVED VISIBLE AND NEARINFRARED SPECTROSCOPY)
[8]	EARN	1.) Mueller, T.G. et al. (2013) Astron. Astrophys. 558, A97. (Physical properties of asteroid 308635 (2005 YU55) derived from multi-instrument infrared observations during a very close Earth approach) 2.) Mueller, T. et al. (2011) I.A.U. Circ. HREF="http://www.cbat.eps.harvard.edu/iauc/09200/09241.html"> 9241. (2005 YU_55) (IR-observation with Herschel) 3.) Hicks, M. et al. (2011) href="http://www.astronomerstelegram.org/?read=3763"> ATel#3763 (Broadband photometry of 2005 YU55: Solar phase behavior and absolute magnitude) 4.) Mueller, T.G. et al. (2013) Astron. Astrophys. 558, A97. (Physical Properties of Asteroid (308635) 2005 YU55 derived from multi-instrument infrared observations during a very close Earth-Approach) 5.) Mueller, T.G. et al. (2011) Astron. Astrophys 525, A145. (Thermo-physical properties of 162173 (1999 JU3), a potential flyby and rendezvous target for interplanetary missions) 6.) Moskovitz, N.A. et al. (2012) ACM2012, 6382. (THE NEAR-EARTH ENCOUNTER OF 2005 YU55: TIME-RESOLVED VISIBLE AND NEARINFRARED SPECTROSCOPY)
[9]	EARN	1.) Vereshchagina, A.I. (2014) Solar System Res. 48, 382-390. (Astrometry and photometry of asteroid (308635) 2005 YU55)
[10]	EARN	1.) Hicks, M. et al. (2010) href="http://www.astronomerstelegram.org/?read=2571"> ATel#2571 (Palomar Spectroscopy of 2001 FM129, 2004 FG11, and 2005 YU55) 2.) Lim, L.F. et al. (2012) LPSC 43, 2202. (The Near-Earth Encounter of 2005 YU55: Thermal Infrared Observations from Gemini North) 3.) Moskovitz, N.A. et al.(2012) LPSC 43, 2202. (THE NEAR-EARTH ENCOUNTER OF ASTEROID 2005 YU55: VISIBLE AND NEAR-INFRARED SPECTROSCOPY)
[11]	EARN	1.) href="http://echo.jpl.nasa.gov/asteroids/index.html">JPL's NEO Radar Detection Program Webpage 2.) Taylor, P.A. et al. (2012) AAS 219, 432.11 (Radar Observations of 2005 YU55's Flyby of Earth) (April 2010 flyby) 3.) Busch, M.W. et al. (2012) ACM2012, 6179. (Shape and Spin of Near-Earth Asteroid 308635 (2005 YU55) From Radar Images and Speckle Tracking)

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

5857

Unit

Source

[1]

Unobserved

Value

1673

Unit

Source

[1]

Normalized RMS of residuals

Value

0.348373

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2005-12-24.29832

Unit

Source

[2]

Last Observation

Value

2022-01-06.256608

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

4006 (31)

Unit

Source

[1]

Radar Summary

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

Radar

Value

Unit

Source

First Observation

Value

2010-04-19

Unit

Source

[3]

Last Observation

Value

2011-11-19

Unit

Source

[3]

Delay (Discarded)

Value

9 (0)

Unit

Source

[1]

Doppler (Discarded)

Value

10 (0)

Unit

Source

[1]

Total Radar Observations (Discarded)

Value

19 (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

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Max residual (arcsec):

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Computation parameters

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Final Date: *

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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 308635 2005YU55 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	1950-11-03 11:15	< 1 min	0.1014979	0.1014947	0.0000010
EARTH	1960-04-13 02:16	< 1 min	0.1092877	0.1092831	0.0000015
EARTH	1961-11-01 17:47	< 1 min	0.1296856	0.1296809	0.0000016
EARTH	1971-04-10 06:18	< 1 min	0.1899213	0.1899170	0.0000014
VENUS	1984-12-05 22:27	< 1 min	0.0485918	0.0485904	0.0000005
VENUS	1986-02-21 14:40	< 1 min	0.0439578	0.0439570	0.0000003
VENUS	1990-12-01 10:23	< 1 min	0.0288012	0.0288009	0.0000001
VENUS	1992-02-17 23:40	< 1 s	0.0126288	0.0126286	0.0000001
MARS	2002-07-14 14:28	< 1 s	0.0397093	0.0397092	0.0000000
EARTH	2010-04-19 12:19	< 1 s	0.0151942	0.0151942	0.0000000
EARTH	2011-11-08 23:28	< 1 s	0.0021720	0.0021720	0.0000000
EARTH	2016-11-01 12:26	< 1 s	0.1236507	0.1236503	0.0000001
VENUS	2029-01-19 20:43	< 1 min	0.0023194	0.0023187	0.0000002
EARTH	2036-10-31 10:57	1.2	0.1214687	0.1214242	0.0000148
EARTH	2040-04-14 02:18	1.2	0.1517980	0.1517391	0.0000196
EARTH	2041-11-12 06:35	1.3	0.1017503	0.1016851	0.0000218
EARTH	2045-04-25 03:23	1.8	0.0698895	0.0698192	0.0000234
VENUS	2055-07-01 13:09	2.2	0.0291667	0.0291171	0.0000165
EARTH	2070-10-23 00:32	19.9	0.1936728	0.1933860	0.0000956
EARTH	2075-11-08 07:18	9.0	0.0013974	0.0012749	0.0000577
VENUS	2097-12-12 02:43	> 1 w	0.0124244	0.0034275	0.2007819
VENUS	2099-03-09 01:25	> 1 mo	0.0087605	0.0033454	0.2722587
EARTH	2100-04-25 13:43	> 1 w	0.0979641	0.0163405	0.2153299
VENUS	2104-04-07 20:30	> 1 mo	0.0329955	0.0328525	0.1467685
EARTH	2105-04-13 16:26	> 1 mo	0.1516276	0.0044577	2.3172757
EARTH	2106-11-07 11:15	> 1 mo	0.0322979	0.0011521	3.1391521
MARS	2109-08-26 04:00	> 1 mo	0.0302923	0.0230268	0.6459984
MARS	2113-07-20 21:16	> 1 mo	0.0265886	0.0264681	0.0226250

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
287.77466711	105.88309197	0.00043030	MINIMUM
70.58400820	302.48234700	0.00110001	MINIMUM
358.75822547	203.71600306	0.35667699	SADDLE
179.50464390	24.54337615	0.66991144	SADDLE
358.79408063	23.75594370	1.64365858	SADDLE
179.49021435	204.52715373	2.67016395	MAXIMUM

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MOID Plots

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