Asteroids

3361 Orpheus help

Last update: 2025-10-25 16:00 UTC

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Apollo

Perihelion (q)

0.819

Aphelion (Q)

1.601

Eccentricity (e)

0.323

Inclination (i)

2.7

deg

Orbit period (P)

486.2

Earth MOID

0.01465

U parameter

0.0

A₂

20.9

10^-15au/days²

Next Earth close approach

Date

2025-11-19

Nominal distance (from Earth center)

0.03792

5673387

Maximum Brightness

15.2

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

19.4

mag

Diameter

348

Taxonomic type

Rotation period (T)

3.547

Discovery Information

Discovery Date

1982-04-24

Observatory

Santiago-Cerro El Roble

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

1.210151

1-sigma variation

1.991E-9

Unit

Eccentricity (e)

Value

0.323161

1-sigma variation

3.420E-8

Unit

Inclination (i)

Value

2.6517

1-sigma variation

1.884E-6

Unit

Long. of Ascending Node (Ω)

Value

188.4428

1-sigma variation

3.015E-5

Unit

Arg. of Perihelion (ω)

Value

302.6452

1-sigma variation

3.032E-5

Unit

Mean Anomaly (M)

Value

320.54811

1-sigma variation

1.867E-6

Unit

Perihelion distance

Value

0.819077

1-sigma variation

Unit

Aphelion distance

Value

1.601224

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

-0.076731

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.311023

1-sigma variation

Unit

MOID

Value

0.014646

1-sigma variation

Unit

Orbit Period

Value

486.2479

1-sigma variation

Unit

U parameter

Value

0.0

1-sigma variation

Unit

A₂

Value

20.94951

1-sigma variation

2.01197

Unit

10^-15au/days²

Covariance Matrix

	a	e	i	Ω	ω	M	A₂
a	3.96241E-18	7.45095E-18	-9.10738E-16	-4.48077E-15	4.37237E-15	-2.76991E-15	2.19510E-9
e	7.45095E-18	1.16942E-15	9.73431E-15	5.34695E-14	1.14179E-13	-1.93087E-14	3.06862E-8
i	-9.10738E-16	9.73431E-15	3.55006E-12	4.93304E-11	-4.86668E-11	1.50158E-12	6.81166E-7
Ω	-4.48077E-15	5.34695E-14	4.93304E-11	9.09171E-10	-9.00767E-10	4.97003E-12	6.36654E-6
ω	4.37237E-15	1.14179E-13	-4.86668E-11	-9.00767E-10	9.19516E-10	-8.79876E-12	-2.31048E-6
M	-2.76991E-15	-1.93087E-14	1.50158E-12	4.97003E-12	-8.79876E-12	3.48501E-12	-1.58600E-6
A₂	2.19510E-9	3.06862E-8	6.81166E-7	6.36654E-6	-2.31048E-6	-1.58600E-6	4.04802E0

Date of computation: 2025-10-25 16:00 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

3.547

3.510

3.533

Unit

Source

[2]

[7]

[1]

Quality

Value

Unit

Source

[7]

Amplitude

Value

0.25

0.19

0.23

Unit

mag

Source

[7]

[2]

[1]

Rotation Direction

Value

Unit

Source

[-]

Spinvector L

Value

Unit

Source

[1]

Spinvector B

Value

-2

Unit

Source

[1]

Taxonomy
Taxonomy (all)

Taxonomy

Value

Unit

Source

Taxonomy

Value

Unit

Source

[3]

[4]

Taxonomy (all)

Value

V;Q

Unit

Source

[5]

[6]

Absolute Magnitude (H)
Slope Parameter (G)

H / G

Value

Unit

Source

Absolute Magnitude (H)

Value

19.441

19.3

Unit

mag

Source

[8]

[9]

Slope Parameter (G)

Value

0.15**

Unit

mag

Source

[8]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.357

Unit

Source

[10]

Diameter

Value

348

Unit

Source

[10]

Color Index Information

Color Index Information

Value

Unit

Source

Color Index Information

Value

Unit

mag

Source

[-]

Sightings

Sightings

Value

Unit

Source

Sightings

Value

Visual S

Radar R

Unit

Source

[11]

[12]

Download this part as:

Sources

No.	Name	Additional
[1]	EARN	1.) Lowell Observatory Near-Earth Asteroid Photometric Survey (NEAPS): Paper 3. Skiff, Brian A et al.
[2]	EARN	1.) A. V. Sergeyev, B. Carry et al A&A, 658 (2022) A109
[3]	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)
[4]	EARN	1.) Alexey V. Sergeyev and Benoit Carry A&A, 652 (2021) A59
[5]	EARN	1.) Wisniewski, W.Z. (1991) Icarus 90, 117-122. (Physical studies of small asteroids. I - Lightcurves and taxonomy of 10 asteroids) 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)
[6]	EARN	Earth Asteroids Research Node: https://earn.dlr.de
[7]	EARN	1.) Polishook, D. (2012) MPB 39, 187-192. (LIGHTCURVES AND SPIN PERIODS OF NEAR-EARTH ASTEROIDS, THE WISE OBSERVATORY, 2005 - 2010) (1862,3361,5143,10115,40267,66251,68216,86829, 105140,138893,141432,141495,152931,185851,2009UN3) 2.) Wisniewski, W.Z. (1991) Icarus 90, 117-122. (Physical studies of small asteroids. I - Lightcurves and taxonomy of 10 asteroids)
[8]	ESA Aegis	ESA orbit determination and impact monitoring system
[9]	EARN	1.) Wisniewski, W.Z. (1991) Icarus 90, 117-122. (Physical studies of small asteroids. I - Lightcurves and taxonomy of 10 asteroids)
[10]	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.) Binzel, R.P. et al. (2002) in "Asteroids III" (Eds. W.F.Bottke et al.), Univ.Ariz.Press, Tucson, USA, pp. 255-271. (Physical Properties of NEOs) 3.) Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; et al. (2011) Astrophys. J. 741, A90. See also Grav 2012b and Masiero 2012.
[11]	EARN	1.) Binzel, R.P. et al. (2006) LPSC 37, 1491. (The MIT-Hawaii-IRTF joint campaign for NEO spectral reconnaissance.) 2.) Binzel, R.P. et al. href="http://smass.mit.edu/minus.html"> Webpage 3.) Burbine, T.H. et al. (2008) ACM2008, 8274. (DETERMINING THE PYROXENE MINERALOGIES OF NEAR-EARTH, MIDDLE-BELT, AND OUTER-BELT VESTOIDS)
[12]	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

15890

Unit

Source

[1]

Unobserved

Value

Unit

Source

[1]

Normalized RMS of residuals

Value

0.349625

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

1982-04-24.29999

Unit

Source

[2]

Last Observation

Value

2025-10-25.099225

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

2895 (15)

Unit

Source

[1]

Radar Summary

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

Radar

Value

Unit

Source

First Observation

Value

2021-11-13

Unit

Source

[3]

Last Observation

Value

2021-11-14

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 3361 Orpheus 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	1954-01-10 15:38	< 1 min	0.1565055	0.1565051	0.0000001
EARTH	1958-01-27 12:13	< 1 min	0.1674545	0.1674543	0.0000001
EARTH	1962-02-12 20:33	< 1 min	0.1654884	0.1654882	0.0000001
EARTH	1966-03-01 16:23	< 1 min	0.1499894	0.1499889	0.0000001
EARTH	1970-03-21 18:31	< 1 min	0.1167275	0.1167269	0.0000002
EARTH	1974-04-07 05:46	< 1 min	0.0702929	0.0702923	0.0000002
EARTH	1978-04-13 18:31	< 1 min	0.0320952	0.0320950	0.0000001
EARTH	1982-04-13 19:44	< 1 min	0.0314462	0.0314456	0.0000002
EARTH	1986-04-07 17:14	< 1 min	0.0687685	0.0687679	0.0000002
EARTH	1990-03-22 04:56	< 1 min	0.1165308	0.1165304	0.0000001
EARTH	1994-03-02 10:54	< 1 min	0.1497388	0.1497386	0.0000001
EARTH	1998-02-12 18:30	< 1 min	0.1668144	0.1668143	0.0000000
EARTH	2002-01-27 20:32	< 1 min	0.1695206	0.1695204	0.0000000
EARTH	2006-01-11 13:16	< 1 min	0.1597122	0.1597121	0.0000000
EARTH	2009-12-25 18:29	< 1 min	0.1383461	0.1383460	0.0000000
EARTH	2013-12-07 00:09	< 1 s	0.1031570	0.1031569	0.0000000
EARTH	2017-11-25 16:29	< 1 s	0.0607172	0.0607171	0.0000000
EARTH	2021-11-21 19:19	< 1 s	0.0385607	0.0385607	0.0000000
EARTH	2025-11-19 01:26	< 1 s	0.0379242	0.0379242	0.0000000
EARTH	2029-11-14 21:38	< 1 s	0.0842046	0.0842043	0.0000001
EARTH	2033-11-10 01:27	< 1 s	0.1658700	0.1658696	0.0000001
EARTH	2083-04-26 03:34	< 1 min	0.1193539	0.1193512	0.0000009
EARTH	2087-04-21 16:21	< 1 min	0.0515548	0.0515523	0.0000008
EARTH	2091-04-18 22:48	< 1 min	0.0211269	0.0211265	0.0000002
EARTH	2095-04-21 19:10	< 1 min	0.0529946	0.0529932	0.0000005
EARTH	2099-04-26 08:44	< 1 min	0.1206594	0.1206568	0.0000009

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
57.96148281	104.31294442	0.01464561	MINIMUM
304.02230930	317.19790346	0.03487562	MINIMUM
0.79527034	30.31643706	0.17034327	SADDLE
180.65015192	210.59210122	0.58753462	SADDLE
1.79706879	211.67440966	1.83444098	SADDLE
180.97875149	30.81991818	2.58663896	MAXIMUM

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MOID Plots

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