207945
Add to an observing list or journal →207945 (1991 JW)
207945 is an asteroid in the Apollo orbit class. Its orbit takes it from 0.92 AU to 1.16 AU from the Sun; one orbit takes 386.9 days; it is about 0.42 km across. Discovered 8 May 1991 by Lawrence, K. J., Helin, E. F.. Orbit from the JPL solution of 17 September 2026.
Where is it now
- Distance from Sun
- 1.006 AU
- True anomaly
- 81.34°
- Distance from Earth
- 0.597 AU
- As of
- 4 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 11m 09s
- Declination
- +17° 26′ 56″
- Constellation
- Leo
- Distance from Earth
- 0.6 AU
- Elongation from the Sun
- 74.02° — well clear of the Sun
Favours the northern hemisphere; low or below the horizon from far south.
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
- 1.039 AU
- Eccentricity
- 0.1187
- Inclination
- 8.71°
- Orbital period
- 386.9 days
- Perihelion
- 0.916 AU
- Aphelion
- 1.162 AU
- Longitude of ascending node
- 53.85°
- Argument of periapsis
- 301.97°
- Epoch · J2000
- 2461200.5
- Orbit class · APO
- Apollo
- Earth MOID · 8.1 LD
- 0.0208 AU
- Tisserand (Jupiter)
- 5.885
Orbit quality
Orbit very well determined (uncertainty code 0).
- Observations used
- 366
- Data arc
- 71.42 years
- First observed
- 16 April 1955
- Last observed
- 16 September 2026
- Residual RMS
- 0.46 ″
- Solution · Otto Matic
- 17 September 2026
Physical properties
- Mean radius
- 0.21 km
- Rotation period
- 3.15 hours
Visual & observation
- Geometric albedo
- 0.161
- Absolute magnitude (H)
- 19.61
Discovery & classification
- Discovered by
- Lawrence, K. J., Helin, E. F.
- Discovery date
- 8 May 1991
- Discovery site
- Palomar
Also known as 1991 JW
Close approaches 45 on record
Top-down view of the ecliptic, Earth at the centre, for the 2027-05-19 16:47 UTC close approach of 207945. Catalogue miss distance 38.9 LD · 1.5 × 10⁷ km. The curve is the geocentric path from 2027-05-16 to 2027-05-22, 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 |
|---|---|---|---|---|
| 2027-05-19 16:47:00 | Earth | 0.1 AU | 38.9 LD | 5 km/s |
| 2028-11-30 20:45:00 | Earth | 0.1345 AU | 52.3 LD | 8.8 km/s |
| 2044-06-02 14:28:00 | Earth | 0.1756 AU | 68.3 LD | 9.3 km/s |
| 2045-04-26 12:46:00 | Earth | 0.1636 AU | 63.7 LD | 5 km/s |
| 2045-10-22 19:36:00 | Earth | 0.1226 AU | 47.7 LD | 4.9 km/s |
| 2062-06-03 08:32:00 | Earth | 0.1179 AU | 45.9 LD | 7.7 km/s |
| 2063-04-12 09:41:00 | Earth | 0.192 AU | 74.7 LD | 5 km/s |
| 2063-11-10 15:59:00 | Earth | 0.0708 AU | 27.6 LD | 5 km/s |
| 2080-06-01 18:02:00 | Earth | 0.1879 AU | 73.1 LD | 9.7 km/s |
| 2081-05-01 19:49:00 | Earth | 0.1496 AU | 58.2 LD | 5 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)
- physical properties: JPL SBDB (lookup)
- visual properties: JPL SBDB (lookup)
- orbital elements: JPL SBDB