Asteroids

2021PP help

Last update: 2025-07-29 02:36 UTC

Orbital Properties

Epoch

60800.0

MJD

Orbit type

Apollo

Perihelion (q)

0.879

Aphelion (Q)

1.857

Eccentricity (e)

0.357

Inclination (i)

3.4

deg

Orbit period (P)

584.6

Earth MOID

0.01056

U parameter

7.0

Next Earth close approach

Date

2029-08-12

Nominal distance (from Earth center)

0.02396

3584251

Maximum Brightness

20.5

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

24.1

mag

Diameter

40 - 90*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-08-03

Observatory

ATLAS-MLO, Mauna Loa

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

60800.0000

1-sigma variation

Unit

MJD

Semimajor Axis

Value

1.368283

1-sigma variation

0.000267

Unit

Eccentricity (e)

Value

0.357229

1-sigma variation

0.000154

Unit

Inclination (i)

Value

3.4304

1-sigma variation

0.0011

Unit

Long. of Ascending Node (Ω)

Value

146.1562

1-sigma variation

0.0007

Unit

Arg. of Perihelion (ω)

Value

229.7758

1-sigma variation

0.0010

Unit

Mean Anomaly (M)

Value

91.37010

1-sigma variation

0.22794

Unit

Perihelion distance

Value

0.879493

1-sigma variation

Unit

Aphelion distance

Value

1.857073

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.563026

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

-0.041493

1-sigma variation

Unit

MOID

Value

0.010564

1-sigma variation

Unit

Orbit Period

Value

584.6048

1-sigma variation

Unit

U parameter

Value

7.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	7.14019E-8	4.11994E-8	2.86779E-7	1.95004E-7	-2.54307E-7	-6.09075E-5
e	4.11994E-8	2.37723E-8	1.65472E-7	1.12525E-7	-1.46735E-7	-3.51440E-5
i	2.86779E-7	1.65472E-7	1.15218E-6	7.81712E-7	-1.02019E-6	-2.44629E-4
Ω	1.95004E-7	1.12525E-7	7.81712E-7	5.39116E-7	-6.99348E-7	-1.66344E-4
ω	-2.54307E-7	-1.46735E-7	-1.02019E-6	-6.99348E-7	9.11002E-7	2.16930E-4
M	-6.09075E-5	-3.51440E-5	-2.44629E-4	-1.66344E-4	2.16930E-4	5.19556E-2

Date of computation: 2025-07-29 02:36 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

24.107

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

40 - 90*

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

Unit

Source

[1]

Unobserved

Value

1474

Unit

Source

[1]

Normalized RMS of residuals

Value

0.483808

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-08-03.430422

Unit

Source

[2]

Last Observation

Value

2021-08-08.90035

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

156 (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 2021PP 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	1952-08-13 08:25	> 1 mo	0.0348723	0.0122970	0.2098774
EARTH	1960-09-17 05:57	> 1 mo	0.1154258	0.0595520	0.0706527
EARTH	1968-10-28 21:16	> 1 mo	0.1148320	0.0759905	0.0527650
EARTH	1976-12-01 09:37	> 1 w	0.0557339	0.0557245	0.0012415
EARTH	1984-12-13 20:02	> 1 d	0.1597403	0.0554422	0.0620505
EARTH	2005-07-24 04:51	834.1	0.1906939	0.1578133	0.0109676
EARTH	2013-08-04 23:09	> 1 d	0.0360254	0.0110725	0.0130505
EARTH	2021-08-08 23:45	< 1 s	0.0107595	0.0107471	0.0000041
EARTH	2029-08-12 01:26	> 1 d	0.0239592	0.0109138	0.0117194
EARTH	2037-09-17 05:19	> 1 w	0.1146306	0.0967493	0.0061966
EARTH	2045-11-01 20:27	> 1 w	0.1117378	0.0737406	0.0187184
EARTH	2053-12-05 10:14	> 1 d	0.0639594	0.0574271	0.0311301
EARTH	2082-08-03 02:01	> 1 w	0.0630064	0.0109329	0.1620174
EARTH	2090-08-20 08:02	> 1 d	0.0573839	0.0345892	0.0077656
EARTH	2098-10-07 10:38	> 1 mo	0.1263144	0.1257506	0.0035022
EARTH	2106-11-28 06:30	> 1 mo	0.0673589	0.0574847	0.1636064
EARTH	2114-12-15 01:28	> 1 mo	0.1437077	0.0574873	0.5940568

Download as:

Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
316.97509988	214.63935874	0.01056404	MINIMUM
38.89616110	328.53728714	0.05726151	MINIMUM
359.42126856	273.86748961	0.12664404	SADDLE
178.99619880	92.45158599	0.85860123	SADDLE
357.35995405	90.87510259	1.87951871	SADDLE
178.59109051	272.17322644	2.85541796	MAXIMUM

Download:

MOID Plots

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