Asteroids

2021RF12 help

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

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Apollo

Perihelion (q)

0.876

Aphelion (Q)

2.911

Eccentricity (e)

0.537

Inclination (i)

2.9

deg

Orbit period (P)

951.7

Earth MOID

0.00059

U parameter

7.6

Next Earth close approach

Date

2034-09-25

Nominal distance (from Earth center)

0.1745

26105315

Maximum Brightness

26.8

mag

Risk

Object is in risk list

Physical Properties

Absolute Magnitude (H)

27.9

mag

Diameter

7 - 16*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-09-12

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

1.893525

1-sigma variation

0.001384

Unit

Eccentricity (e)

Value

0.537483

1-sigma variation

0.000368

Unit

Inclination (i)

Value

2.8574

1-sigma variation

0.0014

Unit

Long. of Ascending Node (Ω)

Value

168.4232

1-sigma variation

0.0004

Unit

Arg. of Perihelion (ω)

Value

128.0636

1-sigma variation

0.0013

Unit

Mean Anomaly (M)

Value

233.69466

1-sigma variation

0.63443

Unit

Perihelion distance

Value

0.875788

1-sigma variation

Unit

Aphelion distance

Value

2.911263

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

1.020069

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.004014

1-sigma variation

Unit

MOID

Value

0.000594

1-sigma variation

Unit

Orbit Period

Value

951.7111

1-sigma variation

Unit

U parameter

Value

7.6

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	1.91430E-6	5.09417E-7	1.88063E-6	-5.88789E-7	-1.81605E-6	-8.77792E-4
e	5.09417E-7	1.35561E-7	5.00457E-7	-1.56681E-7	-4.83287E-7	-2.33590E-4
i	1.88063E-6	5.00457E-7	1.84763E-6	-5.78370E-7	-1.78428E-6	-8.62353E-4
Ω	-5.88789E-7	-1.56681E-7	-5.78370E-7	1.81368E-7	5.57711E-7	2.69986E-4
ω	-1.81605E-6	-4.83287E-7	-1.78428E-6	5.57711E-7	1.72756E-6	8.32739E-4
M	-8.77792E-4	-2.33590E-4	-8.62353E-4	2.69986E-4	8.32739E-4	4.02506E-1

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

27.877

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

7 - 16*

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

1449

Unit

Source

[1]

Normalized RMS of residuals

Value

0.675347

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-09-12.321021

Unit

Source

[2]

Last Observation

Value

2021-10-03.205879

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

38 (0)

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 2021RF12 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	1962-08-24 13:22	> 1 mo	0.0875711	0.0023143	0.5443432
EARTH	1980-06-29 12:54	> 1 mo	0.1359943	0.0703452	0.1470407
EARTH	1998-05-23 02:09	> 1 w	0.0492160	0.0479643	0.0282411
EARTH	2021-09-10 17:22	< 1 min	0.0050245	0.0050159	0.0000029
EARTH	2034-09-25 00:36	> 1 d	0.1745033	0.0020430	0.0873119
MARS	2049-12-05 06:13	> 1 w	0.0369354	0.0089166	0.1091284
EARTH	2068-05-22 02:28	> 1 w	0.0605563	0.0495607	0.0568207
EARTH	2081-06-05 23:43	> 1 w	0.0808062	0.0501800	0.0520605
MARS	2083-10-16 04:27	> 1 d	0.0112042	0.0071281	0.0450670
EARTH	2094-07-02 15:12	432.8	0.1359946	0.1325216	0.0011609
EARTH	2107-07-30 00:07	> 1 w	0.1398906	0.0940778	0.0169821
MARS	2117-08-23 03:25	> 1 w	0.0385118	0.0055283	0.1141067
EARTH	2120-08-22 03:02	> 1 mo	0.1034083	0.0115501	0.0969642

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
29.24130642	245.91603518	0.00101633	MINIMUM
329.99854137	141.58884519	0.04889734	MINIMUM
358.84938280	192.39353475	0.14366329	SADDLE
359.55262473	13.69078155	1.86094385	SADDLE
179.82405496	14.08364981	1.92837495	SADDLE
179.90275257	194.12415148	3.92658707	MAXIMUM

Download:

MOID Plots

Click on the images to zoom-in and zoom-out

Level lines of the squared distance function

2021RF12

Date in UTC	MJD	σ	Distance ± Width in RE	Stretching in RE	IP	Impact energy	PS
2055-09-11.219	71886.219	1.684	0.29 ± 0.000	1.01E4	2.52E-5	2.81E-2	-5.81
2068-09-10.524	76634.524	0.904	1.29 ± 0.000	6.25E3	3.60E-5	2.78E-2	-5.82
2071-09-10.985	77729.985	4.979	0.71 ± 0.000	2.08E5	1.84E-11	2.86E-2	-12.13
2083-09-11.136	82113.136	-2.637	0.35 ± 0.000	3.04E5	1.07E-7	2.69E-2	-8.48


Based on 38 optical observations (of which 0 are rejected as outliers) from 2021/09/12.321 to 2021/10/03.206.
Coordinates are given on the Target Plane.
Unit is one Earth radius, but impact cross section has radius between 1.35 and 1.35 Earth radii.
Coordinates for LOV = EQU scaled= 1 second= F.
AstOD software version= 4.0, Date of computation=20250805 130500.123 UTC.

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Download Impactor Table as: