Asteroids

3361 Orpheus help

Last update: 2026-03-18 10:55 UTC

Orbital Properties

Epoch

61200.0

MJD

Orbit type

Apollo

Perihelion (q)

0.819

Aphelion (Q)

1.600

Eccentricity (e)

0.323

Inclination (i)

2.6

deg

Orbit period (P)

485.8

Earth MOID

0.01449

U parameter

0.0

A₂

22.1

10^-15au/days²

Next Earth close approach

Date

2029-11-14

Nominal distance (from Earth center)

0.0842

12596812

Maximum Brightness

16.9

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

19.4

mag

Diameter

348

Taxonomic type

Rotation period (T)

3.533

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

61200.0000

1-sigma variation

Unit

MJD

Semimajor Axis

Value

1.209480

1-sigma variation

8.690E-10

Unit

Eccentricity (e)

Value

0.322782

1-sigma variation

3.270E-8

Unit

Inclination (i)

Value

2.6465

1-sigma variation

1.684E-6

Unit

Long. of Ascending Node (Ω)

Value

188.2569

1-sigma variation

2.940E-5

Unit

Arg. of Perihelion (ω)

Value

302.8558

1-sigma variation

2.970E-5

Unit

Mean Anomaly (M)

Value

108.69582

1-sigma variation

1.252E-6

Unit

Perihelion distance

Value

0.819081

1-sigma variation

Unit

Aphelion distance

Value

1.599878

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

-0.075917

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.311388

1-sigma variation

Unit

MOID

Value

0.014486

1-sigma variation

Unit

Orbit Period

Value

485.8433

1-sigma variation

Unit

U parameter

Value

0.0

1-sigma variation

Unit

A₂

Value

22.10373

1-sigma variation

1.80693

Unit

10^-15au/days²

Covariance Matrix

	a	e	i	Ω	ω	M	A₂
a	7.55154E-19	1.02918E-17	5.38332E-16	5.94184E-15	-4.63798E-15	-4.50049E-16	1.12805E-9
e	1.02918E-17	1.06924E-15	5.75793E-15	4.29480E-14	1.18775E-13	-2.15885E-14	2.50592E-8
i	5.38332E-16	5.75793E-15	2.83661E-12	4.57135E-11	-4.55284E-11	4.33602E-13	8.73945E-7
Ω	5.94184E-15	4.29480E-14	4.57135E-11	8.64156E-10	-8.59887E-10	1.25790E-12	8.12768E-6
ω	-4.63798E-15	1.18775E-13	-4.55284E-11	-8.59887E-10	8.81956E-10	-5.67857E-12	-4.07720E-6
M	-4.50049E-16	-2.15885E-14	4.33602E-13	1.25790E-12	-5.67857E-12	1.56776E-12	-9.53964E-7
A₂	1.12805E-9	2.50592E-8	8.73945E-7	8.12768E-6	-4.07720E-6	-9.53964E-7	3.26498E0

Date of computation: 2026-03-18 10:55 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

3.533

3.547

3.510

Unit

Source

[1]

[2]

[7]

Quality

Value

Unit

Source

[7]

Amplitude

Value

0.19

0.25

0.23

Unit

mag

Source

[2]

[7]

[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

19.3

19.409

Unit

mag

Source

[8]

[9]

Slope Parameter (G)

Value

0.15**

Unit

Source

[9]

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

Radar R

Visual S

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]	EARN	1.) Wisniewski, W.Z. (1991) Icarus 90, 117-122. (Physical studies of small asteroids. I - Lightcurves and taxonomy of 10 asteroids)
[9]	ESA Aegis	ESA orbit determination and impact monitoring system
[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.) href="http://echo.jpl.nasa.gov/asteroids/index.html">JPL's NEO Radar Detection Program Webpage
[12]	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)

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

15915

Unit

Source

[1]

Unobserved

Value

124

Unit

Source

[1]

Normalized RMS of residuals

Value

0.376734

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

2025-11-19.460905

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

3234 (25)

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

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 3361 Orpheus 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	1954-01-10 15:38	< 1 min	0.1565055	0.1565050	0.0000001
EARTH	1958-01-27 12:13	< 1 min	0.1674545	0.1674543	0.0000000
EARTH	1962-02-12 20:33	< 1 min	0.1654884	0.1654882	0.0000001
EARTH	1966-03-01 16:23	< 1 min	0.1499894	0.1499890	0.0000001
EARTH	1970-03-21 18:31	< 1 min	0.1167276	0.1167270	0.0000002
EARTH	1974-04-07 05:46	< 1 min	0.0702930	0.0702924	0.0000002
EARTH	1978-04-13 18:31	< 1 min	0.0320952	0.0320950	0.0000001
EARTH	1982-04-13 19:44	< 1 min	0.0314461	0.0314456	0.0000002
EARTH	1986-04-07 17:14	< 1 min	0.0687684	0.0687678	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	0.1668145	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	0.1383460	0.1383459	0.0000000
EARTH	2013-12-07 00:09	< 1 s	0.1031569	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	0.0842045	0.0842044	0.0000000
EARTH	2033-11-10 01:27	< 1 s	0.1658698	0.1658696	0.0000001
EARTH	2083-04-26 03:34	< 1 min	0.1193545	0.1193523	0.0000008
EARTH	2087-04-21 16:21	< 1 min	0.0515553	0.0515532	0.0000007
EARTH	2091-04-18 22:48	< 1 min	0.0211270	0.0211266	0.0000001
EARTH	2095-04-21 19:10	< 1 min	0.0529943	0.0529931	0.0000004
EARTH	2099-04-26 08:44	< 1 min	0.1206588	0.1206566	0.0000007

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
57.70912473	100.94877050	0.01448650	MINIMUM
303.89431811	314.01179199	0.03485295	MINIMUM
0.56060211	26.99441111	0.16977800	SADDLE
180.53103409	207.39151902	0.58696035	SADDLE
1.55503552	208.34428872	1.83367819	SADDLE
180.86268549	27.62289193	2.58474156	MAXIMUM

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MOID Plots

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