Asteroids

2021EK4 help

Last update: 2024-04-23 14:44 UTC

Orbital Properties

Epoch

60400.0

MJD

Orbit type

Amor

Perihelion (q)

1.072

Aphelion (Q)

3.876

Eccentricity (e)

0.567

Inclination (i)

14.9

deg

Orbit period (P)

1421.2

Earth MOID

0.14262

U parameter

6.0

Next Earth close approach

Date

2052-04-06

Nominal distance (from Earth center)

0.13108

19609615

Maximum Brightness

19.9

mag

Risk

Object is not in risk list

Object is not in priority list

Physical Properties

Absolute Magnitude (H)

22.4

mag

Diameter

90 - 200*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-03-13

Observatory

Purple Mountain Observatory, XuYi Station

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

2.473846

1-sigma variation

0.000273

Unit

Eccentricity (e)

Value

0.566619

1-sigma variation

0.000052

Unit

Inclination (i)

Value

14.9380

1-sigma variation

0.0008

Unit

Long. of Ascending Node (Ω)

Value

176.3972

1-sigma variation

0.0004

Unit

Arg. of Perihelion (ω)

Value

44.7497

1-sigma variation

0.0004

Unit

Mean Anomaly (M)

Value

268.77562

1-sigma variation

0.04589

Unit

Perihelion distance

Value

1.072117

1-sigma variation

Unit

Aphelion distance

Value

3.875575

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.202792

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

1.806686

1-sigma variation

Unit

MOID

Value

0.142623

1-sigma variation

Unit

Orbit Period

Value

1421.2074

1-sigma variation

Unit

U parameter

Value

6.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	7.47728E-8	1.42198E-8	2.08348E-7	-1.21077E-7	1.16418E-7	-1.25492E-5
e	1.42198E-8	2.70422E-9	3.96216E-8	-2.30257E-8	2.21414E-8	-2.38652E-6
i	2.08348E-7	3.96216E-8	5.80865E-7	-3.37207E-7	3.23874E-7	-3.49673E-5
Ω	-1.21077E-7	-2.30257E-8	-3.37207E-7	1.96373E-7	-1.88970E-7	2.03206E-5
ω	1.16418E-7	2.21414E-8	3.23874E-7	-1.88970E-7	1.84292E-7	-1.95390E-5
M	-1.25492E-5	-2.38652E-6	-3.49673E-5	2.03206E-5	-1.95390E-5	2.10615E-3

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

22.414

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

90 - 200*

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 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

1040

Unit

Source

[1]

Normalized RMS of residuals

Value

0.474782

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-03-13.70429

Unit

Source

[2]

Last Observation

Value

2021-06-18.283075

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

107 (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 2021EK4 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	2021-04-06 07:36	< 1 min	0.1573546	0.1573244	0.0000101
EARTH	2052-04-06 05:14	> 1 d	0.1310822	0.1169553	0.0120378
EARTH	2102-03-27 08:34	> 1 d	0.1585686	0.1097766	0.0609179

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