2018 PK21 is an asteroid in the Aten orbit class. Its orbit takes it from 0.9 AU to 1.06 AU from the Sun; one orbit takes 356.1 days. Orbit from the JPL solution of 12 October 2023.
Where is it now
- Distance from Sun
- 0.955 AU
- True anomaly
- 286.02°
- Distance from Earth
- 0.911 AU
- As of
- 2 November 2026
Two-body Kepler propagation — accurate to ~0.1% for major planets over decades, less so for highly-perturbed bodies. Use JPL Horizons for high precision.
In the sky
- Right ascension
- 10h 50m 12s
- Declination
- +08° 00′ 48″
- Constellation
- Leo
- Distance from Earth
- 0.91 AU
- Elongation from the Sun
- 60.05° — well clear of the Sun
Visible from both hemispheres.
From your location
See how high it is right now, whether it is up after civil twilight, and when it rises and sets where you are.
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Two-body approximation, good to about a degree for the planets — enough to find the constellation and know whether it is up.
Orbital elements
- Semi-major axis
- 0.983 AU
- Eccentricity
- 0.0809
- Inclination
- 1.22°
- Orbital period
- 356.1 days
- Perihelion
- 0.904 AU
- Aphelion
- 1.063 AU
- Longitude of ascending node
- 302.61°
- Argument of periapsis
- 227.4°
- Epoch · J2000
- 2461200.5
- Orbit class · ATE
- Aten
- Earth MOID · 1.9 LD
- 0.0049 AU
- Tisserand (Jupiter)
- 6.158
Orbit quality
Orbit very well determined (uncertainty code 2).
- Observations used
- 132
- Data arc
- 833 days
- First observed
- 11 August 2018
- Last observed
- 21 November 2020
- Residual RMS
- 0.47 ″
- Solution · Otto Matic
- 12 October 2023
Visual & observation
- Absolute magnitude (H)
- 25.88
Discovery & classification
Close approaches 53 on record
Top-down view of the ecliptic, Earth at the centre, for the 2055-07-26 00:26 UTC close approach of 2018 PK21. Catalogue miss distance 155.8 LD · 5.99 × 10⁷ km. The curve is the geocentric path from 2055-07-23 to 2055-07-29, with a mark at UTC midnights and an arrow for the direction of motion. The circle is the Moon’s mean orbit; the Moon is plotted at closest approach. A ray shows the Sun’s direction. The labelled distance is the full separation. The drawn radius is the part that lies in the ecliptic plane. The path is a geocentric ecliptic ephemeris from JPL Horizons. The inset is a heliocentric view and is approximate.
| When (UTC) | Body | Distance | Lunar distances | Relative speed |
|---|---|---|---|---|
| 2055-07-26 00:26:00 | Earth | 0.4004 AU | 155.8 LD | 14.1 km/s |
| 2056-07-19 00:00:00 | Earth | 0.2501 AU | 97.3 LD | 9.6 km/s |
| 2057-07-13 08:06:00 | Earth | 0.1006 AU | 39.2 LD | 5.2 km/s |
| 2058-07-29 05:22:00 | Earth | 0.0367 AU | 14.3 LD | 1.6 km/s |
| 2059-03-16 06:17:00 | Earth | 0.0934 AU | 36.3 LD | 2.7 km/s |
| 2059-12-04 05:23:00 | Earth | 0.0232 AU | 9.0 LD | 1.8 km/s |
| 2060-11-27 19:35:00 | Earth | 0.1276 AU | 49.7 LD | 6.1 km/s |
| 2061-11-20 20:30:00 | Earth | 0.2771 AU | 107.8 LD | 10.6 km/s |
| 2062-11-13 20:08:00 | Earth | 0.4272 AU | 166.3 LD | 15.1 km/s |
| 2095-07-21 20:15:00 | Earth | 0.4427 AU | 172.3 LD | 15.3 km/s |
Next ten from today. 1 lunar distance = 384,400 km. Source: JPL close-approach data.
Sources
- visual properties: JPL SBDB (lookup)
- orbital elements: JPL SBDB