Asteroids

3553 Mera help

Last update: 2026-11-06 13:31 UTC

Orbital Properties

Epoch

61400.0

MJD

Orbit type

Amor

Perihelion (q)

1.118

Aphelion (Q)

2.171

Eccentricity (e)

0.320

Inclination (i)

36.8

deg

Orbit period (P)

770.3

Earth MOID

0.29565

U parameter

0.0

Next Earth close approach

Date

Nominal distance (from Earth center)

Maximum Brightness

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

16.5

mag

Diameter

1300 - 2900*

Taxonomic type

S-

Rotation period (T)

3.194

Discovery Information

Discovery Date

1985-05-14

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

61400.0000

1-sigma variation

Unit

MJD

Semimajor Axis

Value

1.644558

1-sigma variation

1.443E-9

Unit

Eccentricity (e)

Value

0.320105

1-sigma variation

2.045E-8

Unit

Inclination (i)

Value

36.7757

1-sigma variation

5.129E-6

Unit

Long. of Ascending Node (Ω)

Value

232.4788

1-sigma variation

4.559E-6

Unit

Arg. of Perihelion (ω)

Value

288.9024

1-sigma variation

7.947E-6

Unit

Mean Anomaly (M)

Value

303.55602

1-sigma variation

0.00001

Unit

Perihelion distance

Value

1.118126

1-sigma variation

Unit

Aphelion distance

Value

2.170990

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.328341

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.657835

1-sigma variation

Unit

MOID

Value

0.295652

1-sigma variation

Unit

Orbit Period

Value

770.3218

1-sigma variation

Unit

U parameter

Value

0.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	2.08133E-18	-5.18487E-18	2.45234E-16	-2.07804E-16	-2.03717E-15	-2.47900E-16
e	-5.18487E-18	4.18130E-16	-2.41221E-15	1.91576E-15	-2.85314E-14	1.43628E-14
i	2.45234E-16	-2.41221E-15	2.63088E-11	9.39343E-12	-6.98947E-12	-5.21674E-13
Ω	-2.07804E-16	1.91576E-15	9.39343E-12	2.07802E-11	-1.31314E-11	-2.56568E-12
ω	-2.03717E-15	-2.85314E-14	-6.98947E-12	-1.31314E-11	6.31486E-11	-3.63169E-11
M	-2.47900E-16	1.43628E-14	-5.21674E-13	-2.56568E-12	-3.63169E-11	3.12934E-11

Date of computation: 2026-11-06 13:31 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

3.194

Unit

Source

[2]

Quality

Value

Unit

Source

[2]

Amplitude

Value

0.08

Unit

mag

Source

[2]

Rotation Direction

Value

Unit

Source

[-]

Spinvector L

Value

Unit

Source

[-]

Spinvector B

Value

Unit

Source

[-]

Taxonomy
Taxonomy (all)

Taxonomy

Value

Unit

Source

Taxonomy

Value

S-

Unit

Source

[1]

Taxonomy (all)

Value

S-

Unit

Source

[1]

Absolute Magnitude (H)
Slope Parameter (G)

H / G

Value

Unit

Source

Absolute Magnitude (H)

Value

16.533

16.65

Unit

mag

Source

[3]

[4]

Slope Parameter (G)

Value

0.15**

0.24

Unit

Source

[3]

[5]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.05 - 0.25

Unit

Source

[6]

Diameter

Value

1300 - 2900*

Unit

Source

[6]

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

Unit

Source

[1]

Download this part as:

Sources

No.	Name	Additional
[1]	EARN	1.) Lazzarin, M., Marchi,S. & Magrin, S. (2010) href="http://www.astro.unipd.it/planets/sineo/data.html"> SINEO Database (Spectroscopic Investiation of Near-Earth Objects)
[2]	EARN	1.) Galad, A. et al. (2005) Earth, Moon and Planets 97, 147-163. (Joint lightcurve observations of 10 near-Earth asteroids from Modra and Ondrejov) (3553,22753,31669,40267, 66146,88188,103067,1001CB21,2004LJ1,2004XO14,) 2.) Petr Pravec's Ondrejov NEO Photometric Program Webpage "Prepublished Periods"
[3]	ESA Aegis	ESA orbit determination and impact monitoring system
[4]	EARN	1.) Pravec, P. et al. (2012) Icarus 221, 365-387 (Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations) 2.) Galad, A. et al. (2005) Earth, Moon and Planets 97, 147-163. (Joint lightcurve observations of 10 near-Earth asteroids from Modra and Ondrejov) (3553,22753,31669,40267, 66146,88188,103067,1001CB21,2004LJ1,2004XO14,)
[5]	EARN	1.) Pravec, P. et al. (2012) Icarus 221, 365-387 (Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations)
[6]	Estimation	Estimated from absolute magnitude

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

15153

Unit

Source

[1]

Unobserved

Value

Unit

Source

[1]

Normalized RMS of residuals

Value

0.420384

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

1985-05-11.33542

Unit

Source

[2]

Last Observation

Value

2026-11-05.30428

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

2195 (13)

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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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.

Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
45.63191619	120.58920733	0.29565214	MINIMUM
294.92224912	330.85843108	0.53562890	MINIMUM
343.18883043	33.52790336	0.68455183	SADDLE
169.66907915	234.16444270	1.47017871	SADDLE
354.69191451	232.97361576	2.02545125	SADDLE
190.86944333	72.12843509	3.04825953	MAXIMUM

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MOID Plots

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