Asteroids

2021EP4

Last update: 2023-02-07 20:01 UTC

Orbital Properties

Epoch

60000.0

MJD

Orbit type

Apollo

Perihelion (q)

0.971

Aphelion (Q)

2.187

Eccentricity (e)

0.385

Inclination (i)

5.0

deg

Orbit period (P)

724.7

Earth MOID

0.00227

U parameter

6.1

Next Earth close approach

Date

2023-02-14

Nominal distance (from Earth center)

0.04828

7222730

Maximum Brightness

26.7

mag

Risk

Object is not in risk list

Object is not in priority list

Physical Properties

Absolute Magnitude (H)

29.3

mag

Diameter

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-03-15

Observatory

Tokyo-Kiso

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)
Ascending Node (Ω)
Arg. of Perihelion (ω)
Mean Anomaly (M)
Perihelion
Aphelion
Asc. Node-Earth Sep.
Desc. Node-Earth Sep.
MOID
Orbit Period
U parameter

Value

1-sigma variation

Unit

Epoch

Value

60000.0000

1-sigma variation

Unit

MJD

Semimajor Axis

Value

1.578946

1-sigma variation

0.000103

Unit

Eccentricity (e)

Value

0.385066

1-sigma variation

0.000040

Unit

Inclination (i)

Value

5.0005

1-sigma variation

0.0004

Unit

Ascending Node (Ω)

Value

355.4292

1-sigma variation

0.0003

Unit

Arg. of Perihelion (ω)

Value

154.4203

1-sigma variation

0.0012

Unit

Mean Anomaly (M)

Value

3.71153

1-sigma variation

0.02680

Unit

Perihelion

Value

0.970948

1-sigma variation

Unit

Aphelion

Value

2.186945

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

1.054579

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.003566

1-sigma variation

Unit

MOID

Value

0.002273

1-sigma variation

Unit

Orbit Period

Value

724.6852

1-sigma variation

Unit

U parameter

Value

6.1

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	1.05841E-8	4.14322E-9	4.50742E-8	3.20595E-8	-1.20084E-7	-2.75685E-6
e	4.14322E-9	1.62191E-9	1.76447E-8	1.25500E-8	-4.70136E-8	-1.07919E-6
i	4.50742E-8	1.76447E-8	1.92130E-7	1.36532E-7	-5.11467E-7	-1.17405E-5
Ω	3.20595E-8	1.25500E-8	1.36532E-7	9.71111E-8	-3.63749E-7	-8.35058E-6
ω	-1.20084E-7	-4.70136E-8	-5.11467E-7	-3.63749E-7	1.36671E-6	3.12767E-5
M	-2.75685E-6	-1.07919E-6	-1.17405E-5	-8.35058E-6	3.12767E-5	7.18081E-4

Date of computation: 2022-11-23 04:56 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

29.282

Unit

mag

Source

[1]

Slope Parameter (G)

Value

0.15**

Unit

mag

Source

[1]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

Unit

Source

[-]

Diameter

Value

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

Arc Information

Value

Unit

Source

Arc Length

Value

Unit

Source

[1]

Unobserved

Value

692

Unit

Source

[1]

Astrometry Summary

RMS of Residuals
First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

RMS of Residuals

Value

0.773019

Unit

arcsec

Source

[1]

First Observation

Value

2021-03-15.458495

Unit

Source

[2]

Last Observation

Value

2021-03-18.308412

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

67 (4)

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 2021EP4 from to 2123

Body	Date in UTC	Time uncert. in min	Nominal distance in au	Min. possibile distance in au	Distance uncert. in au
EARTH	1953-03-28 16:24	> 1 mo	0.0693520	0.0029082	0.5391491
EARTH	1955-01-10 01:49	> 1 mo	0.1234927	0.0678177	0.4850449
EARTH	1990-03-09 08:51	> 1 d	0.0159608	0.0010389	0.0091142
EARTH	2021-03-15 18:08	< 1 s	0.0024841	0.0024836	0.0000002
EARTH	2023-02-14 01:44	434.5	0.0482810	0.0473375	0.0003186
EARTH	2025-01-16 10:36	326.0	0.1076348	0.1036076	0.0013577
EARTH	2110-04-06 18:09	> 1 d	0.1220100	0.0520739	0.0234628
EARTH	2112-03-21 00:06	> 1 d	0.0163411	0.0005219	0.0166643
EARTH	2114-03-13 06:07	> 1 w	0.0081904	0.0012845	0.0380601
EARTH	2116-01-26 23:55	> 1 mo	0.0785650	0.0563049	0.2587841

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