Asteroids

1566 Icarus help

Last update: 2026-09-08 13:00 UTC

Orbital Properties

Epoch

61200.0

MJD

Orbit type

Apollo

Perihelion (q)

0.186

Aphelion (Q)

1.970

Eccentricity (e)

0.827

Inclination (i)

22.8

deg

Orbit period (P)

408.8

Earth MOID

0.03380

U parameter

0.0

A₂

-4.1

10^-15au/days²

Next Earth close approach

Date

2043-06-13

Nominal distance (from Earth center)

0.05863

8770809

Maximum Brightness

12.5

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

16.5

mag

Diameter

1440

Taxonomic type

Rotation period (T)

2.273

Discovery Information

Discovery Date

1949-06-27

Observatory

Palomar Mountain

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

1.077994

1-sigma variation

1.296E-9

Unit

Eccentricity (e)

Value

0.827019

1-sigma variation

2.315E-8

Unit

Inclination (i)

Value

22.8016

1-sigma variation

7.034E-6

Unit

Long. of Ascending Node (Ω)

Value

87.9486

1-sigma variation

2.999E-6

Unit

Arg. of Perihelion (ω)

Value

31.4444

1-sigma variation

4.407E-6

Unit

Mean Anomaly (M)

Value

329.18267

1-sigma variation

0.00001

Unit

Perihelion distance

Value

0.186473

1-sigma variation

Unit

Aphelion distance

Value

1.969516

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

-0.784405

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.140734

1-sigma variation

Unit

MOID

Value

0.033805

1-sigma variation

Unit

Orbit Period

Value

408.8115

1-sigma variation

Unit

U parameter

Value

0.0

1-sigma variation

Unit

A₂

Value

-4.07340

1-sigma variation

0.27644

Unit

10^-15au/days²

Covariance Matrix

	a	e	i	Ω	ω	M	A₂
a	1.68076E-18	-5.30643E-19	1.53771E-16	1.35609E-16	-2.55481E-17	-7.26778E-15	3.55447E-10
e	-5.30643E-19	5.35840E-16	-5.39234E-14	2.72682E-14	-8.24806E-14	-2.55063E-14	-5.54621E-11
i	1.53771E-16	-5.39234E-14	4.94756E-11	-2.43484E-12	7.58411E-12	5.42451E-12	6.69229E-8
Ω	1.35609E-16	2.72682E-14	-2.43484E-12	8.99545E-12	-1.13473E-11	-8.56629E-14	6.07586E-8
ω	-2.55481E-17	-8.24806E-14	7.58411E-12	-1.13473E-11	1.94234E-11	2.55116E-12	-4.20291E-8
M	-7.26778E-15	-2.55063E-14	5.42451E-12	-8.56629E-14	2.55116E-12	3.36147E-11	-1.52595E-6
A₂	3.55447E-10	-5.54621E-11	6.69229E-8	6.07586E-8	-4.20291E-8	-1.52595E-6	7.64209E-2

Date of computation: 2026-09-08 13:00 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

2.273

Unit

Source

[6]

Quality

Value

Unit

Source

[6]

Amplitude

Value

0.05-0.22

Unit

mag

Source

[6]

Rotation Direction

Value

Unit

Source

[-]

Spinvector L

Value

270

Unit

Source

[1]

Spinvector B

Value

-81

Unit

Source

[1]

Taxonomy
Taxonomy (all)

Taxonomy

Value

Unit

Source

Taxonomy

Value

Unit

Source

[2]

[3]

Taxonomy (all)

Value

SU;Q

Unit

Source

[4]

[5]

Absolute Magnitude (H)
Slope Parameter (G)

H / G

Value

Unit

Source

Absolute Magnitude (H)

Value

15.95

16.527

Unit

mag

Source

[7]

[8]

Slope Parameter (G)

Value

0.15**

-0.041

Unit

Source

[8]

[7]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.14

Unit

Source

[10]

Diameter

Value

1440

Unit

Source

[9]

Color Index Information

Color Index Information

Value

Unit

Source

Color Index Information

Value

0.1264
0.5241
-0.249
0.8
0.54
0.3977
0.2744
-0.123

Unit

r-i

g-i

i-z

B-V

U-B

g-r

g-z

r-z

Source

[3]

[7]

[3]

Sightings

Sightings

Value

Unit

Source

Sightings

Value

Radar R

Visual S

Unit

Source

[11]

[12]

Download this part as:

Sources

No.	Name	Additional
[1]	EARN	1.) Greenberg, A.H. et al. (2017) Astron. J. 153, 108 (16pp). (Asteroid 1566 Icarus' size, shape, orbit, and Yarkovsky drift from radar observations) 2.) Gehrels, T. et al. (1970) Astron. J. 75, 186-195. (Minor planets and related objects. IV. Asteroid (1566) Icarus.) 3.) Magnusson,P. (1989) in "Asteroids II" (Eds. R.P.Binzel et al.), Univ.Ariz.Press, Tucson, USA, pp. 1180-1190.
[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.) A. V. Sergeyev, B. Carry et al A&A, 658 (2022) A109
[4]	EARN	1.) Chapman, C.R. et al. (1975) Icarus 25, 104-130. (Surface properties of asteroids - A synthesis of polarimetry, radiometry, and spectrophotometry) 2.) Tholen, D.J. (1989) in "Asteroids II" (Eds. R.P.Binzel et al.), Univ.Ariz.Press, Tucson, USA, pp. 1139-1150. 3.) Hicks, M.D. et al. (1998) Icarus 133, 69-78. (The Unusual Spectra of 15 Near-Earth Asteroids and Extinct Comet Candidates)(1566,1620,2063,2102,2201,3200,4953,6053,6489, 7092,8176,1994ES1,1995CR,1996JA1) 4.) 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)
[5]	EARN	Earth Asteroids Research Node: https://earn.dlr.de
[6]	EARN	1.) Gehrels, T. et al. (1970) Astron. J. 75, 186-195. (Minor planets and related objects. IV. Asteroid (1566) Icarus.) 2.) Miner, E. & J. Young (1969) Icarus 10, 436-440. (Photometric Determination of the Rotation Period of 1566 Icarus) 3.) Veverka, J. & W. Liller (1969) Icarus 10, 441-444. (Observations of Icarus: 1968) 4.) De Angelis, G. (1995) Planet. Space Sci. 43, 649-682. (Asteroid spin, pole and shape determinations) (..,1566, 1686,1862,..) 5.) Harris, A.W. (DLR) (1998) Icarus 131, 291-301. (A Thermal Model for Near-Earth Asteroids) 6.) Warner, B.D. (2015) MPB 42, 256-266. (NEAR-EARTH ASTEROID LIGHTCURVE ANALYSIS AT CS3-PALMER DIVIDE STATION: 2015 MARCH-JUNE)(35 NEAs)
[7]	EARN	1.) Tedesco, E.F. (1989) in "Asteroids II" (Eds. R.P.Binzel et al.), Univ.Ariz.Press, Tucson, USA, pp. 1090-1138.
[8]	ESA Aegis	ESA orbit determination and impact monitoring system
[9]	EARN	1.) Greenberg, A.H. et al. (2017) Astron. J. 153, 108 (16pp). (Asteroid 1566 Icarus' size, shape, orbit, and Yarkovsky drift from radar observations) 2.) Harris, A.W. (DLR) & J.S.V Lagerros (2002) in "Asteroids III" (Eds. W.F.Bottke et al.), Univ.Ariz.Press, Tucson, USA, pp. 205-218. (Asteroids in the thermal infrared) 3.) Pettengill, G.H. et al. (1969) Icarus 10, 432-435. (Radar observations of Icarus) 4.) Goldstein, R.M. (1969) Icarus 10, 430-431. (Radar observations of Icarus) 5.) Nugent, C.R. et al. (2015) Astrophys. J. 814_117 (13pp) (NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos)(201 NEOs) 6.) Mainzer, A.; Grav, T.; Masiero, J.; Bauer, J.; et al. (2012) Astrophys. J. Let. 760, L12.
[10]	EARN	1.) Thomas, C.A. et al. (2011) Astron. J. 142, 85. (ExploreNEOs. V. AVERAGE ALBEDO BY TAXONOMIC COMPLEX IN THE NEAR-EARTH ASTEROID POPULATION) (new albedos data for 118 NEOs) 2.) Harris, A.W. (DLR) & J.S.V Lagerros (2002) in "Asteroids III" (Eds. W.F.Bottke et al.), Univ.Ariz.Press, Tucson, USA, pp. 205-218. (Asteroids in the thermal infrared) 3.) Tedesco, E.F. (1989) in "Asteroids II" (Eds. R.P.Binzel et al.), Univ.Ariz.Press, Tucson, USA, pp. 1090-1138. 4.) Veeder, G.J. et al. (1989) Astron. J. 97, 1211-1219. (Radiometry of near-earth asteroids) 5.) Nugent, C.R. et al. (2015) Astrophys. J. 814_117 (13pp) (NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos)(201 NEOs) 6.) Mainzer, A.; Grav, T.; Masiero, J.; Bauer, J.; et al. (2012) Astrophys. J. Let. 760, L12.
[11]	EARN	1.) Goldstein, R.M. (1969) Icarus 10, 430-431. (Radar observations of Icarus) 2.) Mahapatra, P.R. et al. (1998) (1998) B.A.A.S. 30, 1024. 07.04. (A Recent Radar Observation of Asteroid 1566 Icarus) 3.) Pettengill, G.H. et al. (1969) Icarus 10, 432-435. (Radar observations of Icarus) 4.) Ostro, S.J. et al. (1991) Astron. J. 102, 1490-1502. (Asteroid radar astrometry) 5.) Goldstein, R. M., (1968) Science 162, 903-904. (Radar observations of Icarus.) 6.) Mahapatra, P. et al., (1999) Planetary and Space Science 47, 987-995. (Recent radar observations of asteroid 1566 Icarus.)
[12]	EARN	1.) Hicks, M.D. et al. (1998) Icarus 133, 69-78. (The Unusual Spectra of 15 Near-Earth Asteroids and Extinct Comet Candidates)(1566,1620,2063,2102,2201,3200,4953,6053,6489, 7092,8176,1994ES1,1995CR,1996JA1) 2.) Fevig. R.A. and U. Fink (2007) Icarus 188, 175-188. (Spectral observations of 19 weathered and 23 fresh NEAs and their correlations with orbital parameters)(433,1036, 1627,1685,1862,1866,1943,1980,3103,3122,3199,3671,4183,4341, 4954,5587,5751,5836,6037,7358,7482,7753,7822,7977,8201, 10563,11066,13651,13651,19356,20236,20255,35107,85490, J97GD32,J97UH9,J97US9,J98HE3,J98HT31,J98ME3,J98MS2,K04LC2)

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

28196

Unit

Source

[1]

Unobserved

Value

Unit

Source

[1]

Normalized RMS of residuals

Value

0.542447

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

1949-06-27.23889

Unit

Source

[2]

Last Observation

Value

2026-09-07.029465

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

1984 (52)

Unit

Source

[1]

Radar Summary

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

Radar

Value

Unit

Source

First Observation

Value

1968-06-14

Unit

Source

[3]

Last Observation

Value

2015-06-20

Unit

Source

[3]

Delay (Discarded)

Value

10 (0)

Unit

Source

[1]

Doppler (Discarded)

Value

13 (0)

Unit

Source

[1]

Total Radar Observations (Discarded)

Value

23 (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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Close Approaches for 1566 Icarus 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	1968-06-14 20:38	< 1 s	0.0424821	0.0424820	0.0000000
EARTH	1987-06-21 00:46	< 1 s	0.1607287	0.1607284	0.0000001
EARTH	1996-06-11 07:33	< 1 s	0.1011944	0.1011941	0.0000001
EARTH	2015-06-16 15:38	< 1 s	0.0538362	0.0538362	0.0000000
EARTH	2043-06-13 16:56	< 1 s	0.0586292	0.0586285	0.0000002
EARTH	2062-06-18 01:09	< 1 min	0.0834007	0.0833991	0.0000005
EARTH	2071-06-10 12:27	< 1 min	0.1794473	0.1794451	0.0000007
EARTH	2090-06-14 07:07	< 1 min	0.0435390	0.0435366	0.0000008
EARTH	2109-06-19 18:45	< 1 min	0.0988755	0.0988714	0.0000013
EARTH	2118-06-11 21:34	< 1 min	0.1621016	0.1620975	0.0000014

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
86.51634595	158.80371755	0.03380473	MINIMUM
276.50304473	232.29217680	0.36844898	MINIMUM
5.71140146	28.61832108	0.80534348	SADDLE
182.89310820	193.92984935	0.99663312	SADDLE
4.08938508	203.74468393	1.19798859	SADDLE
179.18131111	12.81790158	2.93995112	MAXIMUM

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MOID Plots

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