Asteroids

2021KU2 help

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

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Apollo

Perihelion (q)

0.922

Aphelion (Q)

1.376

Eccentricity (e)

0.198

Inclination (i)

21.3

deg

Orbit period (P)

450.0

Earth MOID

0.00952

U parameter

3.3

Next Earth close approach

Date

2037-12-04

Nominal distance (from Earth center)

0.17909

26792130

Maximum Brightness

20.4

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

22.7

mag

Diameter

80 - 170*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-05-30

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

1.149190

1-sigma variation

0.000001

Unit

Eccentricity (e)

Value

0.197760

1-sigma variation

0.000001

Unit

Inclination (i)

Value

21.2715

1-sigma variation

0.0001

Unit

Long. of Ascending Node (Ω)

Value

84.7214

1-sigma variation

3.034E-5

Unit

Arg. of Perihelion (ω)

Value

247.9648

1-sigma variation

0.0001

Unit

Mean Anomaly (M)

Value

159.29837

1-sigma variation

0.00107

Unit

Perihelion distance

Value

0.921927

1-sigma variation

Unit

Aphelion distance

Value

1.376454

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.208465

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.010587

1-sigma variation

Unit

MOID

Value

0.009524

1-sigma variation

Unit

Orbit Period

Value

449.9730

1-sigma variation

Unit

U parameter

Value

3.3

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	4.41652E-13	4.84329E-13	3.30047E-11	-8.85062E-12	1.15351E-12	-7.09299E-10
e	4.84329E-13	5.38658E-13	3.91848E-11	-1.06781E-11	5.72624E-12	-7.82148E-10
i	3.30047E-11	3.91848E-11	5.34968E-9	-1.91320E-9	3.57796E-9	-5.59596E-8
Ω	-8.85062E-12	-1.06781E-11	-1.91320E-9	9.20589E-10	-1.50394E-9	1.52180E-8
ω	1.15351E-12	5.72624E-12	3.57796E-9	-1.50394E-9	5.36313E-9	-6.74231E-9
M	-7.09299E-10	-7.82148E-10	-5.59596E-8	1.52180E-8	-6.74231E-9	1.14404E-6

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

22.725

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

80 - 170*

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

[-]

Download this part as:

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

223

Unit

Source

[1]

Unobserved

Value

1354

Unit

Source

[1]

Normalized RMS of residuals

Value

0.649233

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-05-30.255955

Unit

Source

[2]

Last Observation

Value

2022-01-08.373913

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

50 (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 2021KU2 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	1957-06-25 03:57	2.0	0.1864346	0.1863230	0.0000372
EARTH	1957-12-07 02:20	2.7	0.1939097	0.1938705	0.0000131
EARTH	1973-06-21 18:19	3.4	0.1134119	0.1132509	0.0000537
EARTH	1989-06-20 03:22	7.7	0.0779267	0.0775715	0.0001184
EARTH	2005-06-21 08:00	5.2	0.1027725	0.1025262	0.0000821
EARTH	2021-06-24 11:59	< 1 min	0.1683567	0.1683539	0.0000009
EARTH	2037-12-04 15:32	5.3	0.1790943	0.1790593	0.0000117
EARTH	2042-06-08 00:36	5.9	0.1989171	0.1985978	0.0001064
EARTH	2053-12-02 11:26	5.9	0.1787957	0.1787297	0.0000221
EARTH	2058-06-11 02:27	9.7	0.1313759	0.1308910	0.0001616
EARTH	2069-12-01 13:59	4.2	0.1892343	0.1890822	0.0000509
EARTH	2074-06-12 15:16	9.4	0.0981664	0.0977147	0.0001506
EARTH	2085-12-01 18:22	1.8	0.1872688	0.1872046	0.0000214
EARTH	2090-06-11 17:14	2.5	0.1195975	0.1194754	0.0000407
EARTH	2101-12-04 01:05	2.7	0.1757606	0.1757383	0.0000075
EARTH	2106-06-09 20:52	5.0	0.1848254	0.1845569	0.0000895
EARTH	2117-12-06 20:26	12.1	0.1814875	0.1813738	0.0000381

Download as:

Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
302.91932414	162.90662438	0.01120239	MINIMUM
86.10953141	329.37047938	0.17624729	MINIMUM
17.20253211	252.32891069	0.36457471	SADDLE
194.12174735	60.63300605	0.56689205	SADDLE
2.38087777	52.90945861	1.88294149	SADDLE
170.29135383	220.23165241	2.35575739	MAXIMUM

Download:

MOID Plots

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