Asteroids

2021RQ4 help

Last update: 2024-04-25 14:31 UTC

Orbital Properties

Epoch

60400.0

MJD

Orbit type

Apollo

Perihelion (q)

0.884

Aphelion (Q)

1.620

Eccentricity (e)

0.294

Inclination (i)

2.9

deg

Orbit period (P)

511.9

Earth MOID

0.00601

U parameter

7.0

Next Earth close approach

Date

2028-09-18

Nominal distance (from Earth center)

0.03902

5836785

Maximum Brightness

25.9

mag

Risk

Object is not in risk list

Object is not in priority list

Physical Properties

Absolute Magnitude (H)

28.7

mag

Diameter

5 - 11*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-09-09

Observatory

Mt. Lemmon Survey

Orbit Visualiser

Click the button to start Orbit Visualiser

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

60400.0000

1-sigma variation

Unit

MJD

Semimajor Axis

Value

1.252283

1-sigma variation

0.000222

Unit

Eccentricity (e)

Value

0.293861

1-sigma variation

0.000162

Unit

Inclination (i)

Value

2.8549

1-sigma variation

0.0017

Unit

Long. of Ascending Node (Ω)

Value

342.3666

1-sigma variation

0.0007

Unit

Arg. of Perihelion (ω)

Value

69.1959

1-sigma variation

0.0025

Unit

Mean Anomaly (M)

Value

259.19091

1-sigma variation

0.16026

Unit

Perihelion distance

Value

0.884286

1-sigma variation

Unit

Aphelion distance

Value

1.620280

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.028113

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.286533

1-sigma variation

Unit

MOID

Value

0.006009

1-sigma variation

Unit

Orbit Period

Value

511.8611

1-sigma variation

Unit

U parameter

Value

7.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	4.93773E-8	3.59109E-8	3.79918E-7	1.64899E-7	-5.60163E-7	-3.56114E-5
e	3.59109E-8	2.61174E-8	2.76297E-7	1.19910E-7	-4.07320E-7	-2.58994E-5
i	3.79918E-7	2.76297E-7	2.92466E-6	1.27133E-6	-4.31478E-6	-2.74000E-4
Ω	1.64899E-7	1.19910E-7	1.27133E-6	5.55202E-7	-1.87979E-6	-1.18925E-4
ω	-5.60163E-7	-4.07320E-7	-4.31478E-6	-1.87979E-6	6.38282E-6	4.03988E-4
M	-3.56114E-5	-2.58994E-5	-2.74000E-4	-1.18925E-4	4.03988E-4	2.56833E-2

Date of computation: 2024-04-23 10:08 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

28.742

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

5 - 11*

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 ODIM	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

957

Unit

Source

[1]

Normalized RMS of residuals

Value

0.660535

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-09-08.87333

Unit

Source

[2]

Last Observation

Value

2021-09-11.89113

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

34 (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

[3]

Last Observation

Value

Unit

Source

[3]

Delay (Discarded)

Value

0 (0)

Unit

Source

[1]

Doppler (Discarded)

Value

0 (0)

Unit

Source

[1]

Total Radar Observations (Discarded)

Value

0 (0)

Unit

Source

[1]

Note: The ASCII file is in a format suitable for Orbfit input.

Sources

No.	Name	Additional
[1]	ESA ODIM	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

Close approaches for 2021RQ4 from 1950 to 2124

Body	Date in UTC	Time uncert. in min	Nominal distance in au	Min. possibile distance in au	Distance uncert. in au
EARTH	1953-01-09 14:11	> 1 w	0.0455122	0.0436524	0.0192166
EARTH	1976-09-01 22:45	239.3	0.1012771	0.0912330	0.0033481
EARTH	1983-09-27 10:14	> 1 d	0.0663217	0.0183162	0.0160034
EARTH	1990-12-11 15:34	> 1 w	0.0958051	0.0572044	0.0147176
EARTH	1998-01-16 17:47	> 1 d	0.1037228	0.0428732	0.0332959
EARTH	2021-09-11 16:39	< 1 min	0.0059745	0.0059652	0.0000031
EARTH	2028-09-18 04:20	> 1 d	0.0390165	0.0089277	0.0103252
EARTH	2035-10-27 13:22	397.7	0.1076774	0.1076015	0.0000253
EARTH	2042-12-09 04:60	> 1 d	0.0984459	0.0822372	0.0055332
EARTH	2050-01-09 09:50	> 1 d	0.0395740	0.0395417	0.0008409
MARS	2052-04-25 10:27	> 1 d	0.0425124	0.0289114	0.0236692
EARTH	2057-01-20 12:53	> 1 d	0.1515272	0.0383817	0.0780819
EARTH	2080-08-30 00:30	> 1 w	0.1555299	0.0042830	0.1906869
EARTH	2087-09-10 18:08	> 1 w	0.0168400	0.0070266	0.1683631
EARTH	2094-09-02 18:46	> 1 mo	0.1070956	0.0053653	1.6449537
MARS	2118-02-19 08:35	> 1 mo	0.0299160	0.0288526	0.8869238

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