277475
Add to an observing list or journal →277475 (2005 WK4)
277475 is an asteroid in the Apollo orbit class. Its orbit takes it from 0.77 AU to 1.25 AU from the Sun; one orbit takes 371 days. Discovered 27 November 2005 by Siding Spring Survey. Orbit from the JPL solution of 1 March 2023.
Where is it now
- Distance from Sun
- 1.058 AU
- True anomaly
- 114.56°
- Distance from Earth
- 1.244 AU
- As of
- 3 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
- 18h 29m 08s
- Declination
- -24° 33′ 19″
- Constellation
- Sagittarius
- Distance from Earth
- 1.25 AU
- Elongation from the Sun
- 55.1° — near the Sun — look low at dusk or dawn
Favours the southern hemisphere; low or below the horizon from far north.
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
- 1.011 AU
- Eccentricity
- 0.2373
- Inclination
- 9.84°
- Orbital period
- 371 days
- Perihelion
- 0.771 AU
- Aphelion
- 1.25 AU
- Longitude of ascending node
- 138.11°
- Argument of periapsis
- 74.13°
- Epoch · J2000
- 2461200.5
- Orbit class · APO
- Apollo
- Earth MOID · 1.3 LD
- 0.0033 AU
- Tisserand (Jupiter)
- 5.993
Orbit quality
Orbit very well determined (uncertainty code 0).
- Observations used
- 332
- Data arc
- 9.75 years
- First observed
- 27 November 2005
- Last observed
- 30 August 2015
- Residual RMS
- 0.54 ″
- Solution · Otto Matic
- 1 March 2023
Physical properties
- Rotation period
- 2.6 hours
Visual & observation
- Absolute magnitude (H)
- 20.22
Discovery & classification
- Discovered by
- Siding Spring Survey
- Discovery date
- 27 November 2005
- Discovery site
- Siding Spring
Also known as 2005 WK4
Close approaches 139 on record
Top-down view of the ecliptic, Earth at the centre, for the 2062-12-28 22:26 UTC close approach of 277475. Catalogue miss distance 192.3 LD · 7.39 × 10⁷ km. The curve is the geocentric path from 2062-12-25 to 2062-12-31, 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 |
|---|---|---|---|---|
| 2035-09-08 00:14:00 | Venus | 0.0846 AU | 32.9 LD | 6.3 km/s |
| 2055-12-23 15:06:00 | Venus | 0.1242 AU | 48.3 LD | 5.3 km/s |
| 2059-01-23 02:35:00 | Venus | 0.137 AU | 53.3 LD | 9.5 km/s |
| 2062-12-28 22:26:00 | Earth | 0.4941 AU | 192.3 LD | 23 km/s |
| 2064-01-02 17:52:00 | Earth | 0.3972 AU | 154.6 LD | 20 km/s |
| 2065-01-06 18:01:00 | Earth | 0.3001 AU | 116.8 LD | 17.1 km/s |
| 2066-01-11 19:11:00 | Earth | 0.2043 AU | 79.5 LD | 14.3 km/s |
| 2067-01-17 06:21:00 | Earth | 0.1133 AU | 44.1 LD | 11.5 km/s |
| 2068-01-23 10:45:00 | Earth | 0.054 AU | 21.0 LD | 9.1 km/s |
| 2069-01-31 21:29:00 | Earth | 0.101 AU | 39.3 LD | 7.2 km/s |
Next ten from today. 1 lunar distance = 384,400 km. Source: JPL close-approach data.
Sources
- visual properties: JPL SBDB (lookup)
- physical properties: JPL SBDB (lookup)
- orbital elements: JPL SBDB