Asteroids

2021RE help

Last update: 2025-09-10 00:30 UTC

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Apollo

Perihelion (q)

0.964

Aphelion (Q)

1.611

Eccentricity (e)

0.251

Inclination (i)

20.7

deg

Orbit period (P)

533.8

Earth MOID

0.01021

U parameter

8.0

Next Earth close approach

Date

2040-09-09

Nominal distance (from Earth center)

0.02741

4099801

Maximum Brightness

17.5

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

mag

Diameter

70 - 150*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-09-03

Observatory

Mt. Lemmon Survey

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

1.287798

1-sigma variation

0.000946

Unit

Eccentricity (e)

Value

0.251116

1-sigma variation

0.000566

Unit

Inclination (i)

Value

20.6766

1-sigma variation

0.0260

Unit

Long. of Ascending Node (Ω)

Value

166.4946

1-sigma variation

0.0031

Unit

Arg. of Perihelion (ω)

Value

137.1200

1-sigma variation

0.0267

Unit

Mean Anomaly (M)

Value

338.69588

1-sigma variation

1.19472

Unit

Perihelion distance

Value

0.964412

1-sigma variation

Unit

Aphelion distance

Value

1.611184

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.485349

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.011197

1-sigma variation

Unit

MOID

Value

0.010209

1-sigma variation

Unit

Orbit Period

Value

533.7895

1-sigma variation

Unit

U parameter

Value

8.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	8.95695E-7	5.35242E-7	2.45668E-5	-2.90863E-6	2.53020E-5	-1.13070E-3
e	5.35242E-7	3.19845E-7	1.46804E-5	-1.73811E-6	1.51197E-5	-6.75671E-4
i	2.45668E-5	1.46804E-5	6.73813E-4	-7.97773E-5	6.93967E-4	-3.10123E-2
Ω	-2.90863E-6	-1.73811E-6	-7.97773E-5	9.44542E-6	-8.21631E-5	3.67175E-3
ω	2.53020E-5	1.51197E-5	6.93967E-4	-8.21631E-5	7.14764E-4	-3.19404E-2
M	-1.13070E-3	-6.75671E-4	-3.10123E-2	3.67175E-3	-3.19404E-2	1.42735E0

Date of computation: 2025-09-10 00:30 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

[-]

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

[-]

Taxonomy (all)

Value

Unit

Source

[-]

Absolute Magnitude (H)
Slope Parameter (G)

H / G

Value

Unit

Source

Absolute Magnitude (H)

Value

22.981

Unit

mag

Source

[1]

Slope Parameter (G)

Value

0.15**

Unit

mag

Source

[1]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.05 - 0.25

Unit

Source

[2]

Diameter

Value

70 - 150*

Unit

Source

[2]

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]	ESA Aegis	ESA orbit determination and impact monitoring system
[2]	Estimation	Estimated from absolute magnitude

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

Unit

Source

[1]

Unobserved

Value

1450

Unit

Source

[1]

Normalized RMS of residuals

Value

0.491502

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-09-03.138378

Unit

Source

[2]

Last Observation

Value

2021-09-28.14289

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

45 (1)

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

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 2021RE 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	1951-08-29 07:03	> 1 mo	0.1584323	0.0055472	0.7080521
EARTH	1967-09-10 13:21	> 1 w	0.0295552	0.0110777	0.1706220
EARTH	1986-09-01 21:37	> 1 w	0.1070348	0.0041571	0.2098607
EARTH	2021-09-10 15:59	< 1 s	0.0370659	0.0369106	0.0000518
EARTH	2040-09-09 20:45	> 1 w	0.0274055	0.0104694	0.1193389
EARTH	2081-09-08 11:34	> 1 mo	0.0109087	0.0101951	0.4156105
EARTH	2100-09-09 13:04	> 1 mo	0.0101358	0.0101062	3.8038481
EARTH	2119-09-14 07:36	> 1 mo	0.0694598	0.0077642	3214.0084981

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
33.20123466	244.40926227	0.01117121	MINIMUM
282.27562990	106.38990810	0.35069160	MINIMUM
315.87452286	144.98995520	0.36969620	SADDLE
159.96465871	7.46532269	0.71721727	SADDLE
352.03451695	13.17077651	1.93166013	SADDLE
184.42492657	206.39451988	2.60880534	MAXIMUM

Download:

MOID Plots

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