Asteroids

1221 Amor help

Last update: 2026-10-06 13:16 UTC

Orbital Properties

Epoch

61400.0

MJD

Orbit type

Amor

Perihelion (q)

1.085

Aphelion (Q)

2.754

Eccentricity (e)

0.435

Inclination (i)

11.9

deg

Orbit period (P)

971.4

Earth MOID

0.10910

U parameter

0.0

A₂

-7.8

10^-15au/days²

Next Earth close approach

Date

2089-04-07

Nominal distance (from Earth center)

0.19748

29542793

Maximum Brightness

16.3

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

17.5

mag

Diameter

1100

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

1932-03-12

Observatory

Uccle

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

61400.0000

1-sigma variation

Unit

MJD

Semimajor Axis

Value

1.919543

1-sigma variation

3.453E-9

Unit

Eccentricity (e)

Value

0.434865

1-sigma variation

2.294E-8

Unit

Inclination (i)

Value

11.8711

1-sigma variation

3.008E-6

Unit

Long. of Ascending Node (Ω)

Value

171.2378

1-sigma variation

1.519E-5

Unit

Arg. of Perihelion (ω)

Value

26.7502

1-sigma variation

1.652E-5

Unit

Mean Anomaly (M)

Value

208.09123

1-sigma variation

0.00001

Unit

Perihelion distance

Value

1.084801

1-sigma variation

Unit

Aphelion distance

Value

2.754285

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.128078

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

1.540065

1-sigma variation

Unit

MOID

Value

0.109103

1-sigma variation

Unit

Orbit Period

Value

971.3938

1-sigma variation

Unit

U parameter

Value

0.0

1-sigma variation

Unit

A₂

Value

-7.76366

1-sigma variation

1.53851

Unit

10^-15au/days²

Covariance Matrix

	a	e	i	Ω	ω	M	A₂
a	1.19230E-17	-6.16448E-18	-1.32190E-16	2.67161E-15	8.14910E-15	-2.21364E-14	5.20956E-9
e	-6.16448E-18	5.26063E-16	3.80328E-15	3.71845E-16	-7.92189E-15	1.39206E-14	1.56297E-9
i	-1.32190E-16	3.80328E-15	9.05091E-12	-5.94980E-12	6.23518E-12	-4.35119E-13	-3.42982E-7
Ω	2.67161E-15	3.71845E-16	-5.94980E-12	2.30629E-10	-2.32238E-10	7.55363E-12	2.86091E-6
ω	8.14910E-15	-7.92189E-15	6.23518E-12	-2.32238E-10	2.73020E-10	-5.78485E-11	1.21529E-6
M	-2.21364E-14	1.39206E-14	-4.35119E-13	7.55363E-12	-5.78485E-11	7.94113E-11	-8.89334E-6
A₂	5.20956E-9	1.56297E-9	-3.42982E-7	2.86091E-6	1.21529E-6	-8.89334E-6	2.36701E0

Date of computation: 2026-10-06 13:16 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

Unit

Source

[-]

Quality

Value

Unit

Source

[6]

Amplitude

Value

Unit

mag

Source

[-]

Rotation Direction

Value

Unit

Source

[-]

Spinvector L

Value

Unit

Source

[-]

Spinvector B

Value

Unit

Source

[-]

Taxonomy
Taxonomy (all)

Taxonomy

Value

Unit

Source

Taxonomy

Value

Unit

Source

[1]

Taxonomy (all)

Value

Unit

Source

[2]

Absolute Magnitude (H)
Slope Parameter (G)

H / G

Value

Unit

Source

Absolute Magnitude (H)

Value

17.485

17.46

Unit

mag

Source

[3]

[4]

Slope Parameter (G)

Value

0.15**

Unit

Source

[3]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

medium

Unit

Source

[5]

Diameter

Value

1100

Unit

Source

[5]

Color Index Information

Color Index Information

Value

Unit

Source

Color Index Information

Value

Unit

mag

Source

[-]

Sightings

Sightings

Value

Unit

Source

Sightings

Value

Unit

Source

[-]

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Sources

No.	Name	Additional
[1]	EARN	1.) Alexey V. Sergeyev and Benoit Carry A&A, 652 (2021) A59
[2]	EARN	Earth Asteroids Research Node: https://earn.dlr.de
[3]	ESA Aegis	ESA orbit determination and impact monitoring system
[4]	EARN	1.) Wisniewski, W.Z. et al. (1997) Icarus 126, 395-449. (Photometric Observations of 125 Asteroids)
[5]	EARN	1.) 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)
[6]	EARN	1.) Wisniewski, W.Z. et al. (1997) Icarus 126, 395-449. (Photometric Observations of 125 Asteroids) 2.) Wisniewski, W.Z. et al. (1995) LPSC XXVI, 1511-1512. (Photoelectric Observations of 125 Asteroids)

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

34540

Unit

Source

[1]

Unobserved

Value

Unit

Source

[1]

Normalized RMS of residuals

Value

0.586276

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

1932-03-12.92014

Unit

Source

[2]

Last Observation

Value

2026-10-05.556272

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

765 (19)

Unit

Source

[1]

Radar Summary

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

Radar

Value

Unit

Source

First Observation

Value

Unit

Source

[-]

Last Observation

Value

Unit

Source

[-]

Delay (Discarded)

Value

0 (0)

Unit

Source

[-]

Doppler (Discarded)

Value

0 (0)

Unit

Source

[-]

Total Radar Observations (Discarded)

Value

0 (0)

Unit

Source

[-]

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

Filters

Initial Date: *

Final Date: *

Normalised Only accepted

Max residual (arcsec):

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Plot

Computation parameters

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Initial Date: *

Final Date: *

Output option:

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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 1221 Amor 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	1956-03-21 06:18	< 1 min	0.1148122	0.1148119	0.0000001
EARTH	1964-03-19 02:53	< 1 min	0.1281804	0.1281800	0.0000001
EARTH	1972-03-14 08:54	< 1 min	0.1954110	0.1954103	0.0000002
EARTH	2089-04-07 05:20	< 1 min	0.1974814	0.1974778	0.0000012
EARTH	2097-03-31 04:54	< 1 min	0.1405232	0.1405205	0.0000009
EARTH	2105-03-28 01:52	< 1 min	0.1139743	0.1139728	0.0000005
EARTH	2113-03-28 03:50	< 1 min	0.1153412	0.1153391	0.0000007
EARTH	2121-03-27 04:21	< 1 min	0.1109461	0.1109438	0.0000008

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
351.00968391	79.67660049	0.10910297	MINIMUM
181.84358032	276.00816958	1.76368949	SADDLE
2.76519800	278.06052530	2.07950781	SADDLE
180.12938006	94.94710336	3.75145332	MAXIMUM

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MOID Plots

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