2017 BU is an asteroid in the Apollo orbit class. Its orbit takes it from 0.76 AU to 1.28 AU from the Sun; one orbit takes 376.1 days. Orbit from the JPL solution of 21 September 2022.
Where is it now
- Distance from Sun
- 1.104 AU
- True anomaly
- 122.53°
- Distance from Earth
- 0.792 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
- 19h 59m 43s
- Declination
- -22° 39′ 48″
- Constellation
- Sagittarius
- Distance from Earth
- 0.8 AU
- Elongation from the Sun
- 75.62° — well clear of the Sun
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
- 1.02 AU
- Eccentricity
- 0.2514
- Inclination
- 1.5°
- Orbital period
- 376.1 days
- Perihelion
- 0.763 AU
- Aphelion
- 1.276 AU
- Longitude of ascending node
- 74.81°
- Argument of periapsis
- 159.99°
- Epoch · J2000
- 2461200.5
- Orbit class · APO
- Apollo
- Earth MOID · 8.9 LD
- 0.0229 AU
- Tisserand (Jupiter)
- 5.96
Orbit quality
Orbit very well determined (uncertainty code 0).
- Observations used
- 76
- Data arc
- 5.67 years
- First observed
- 19 January 2017
- Last observed
- 20 September 2022
- Residual RMS
- 0.5 ″
- Solution · Otto Matic
- 21 September 2022
Visual & observation
- Absolute magnitude (H)
- 25.21
Discovery & classification
Close approaches 156 on record
Top-down view of the ecliptic, Earth at the centre, for the 2049-01-20 03:22 UTC close approach of 2017 BU. Catalogue miss distance 164.8 LD · 6.34 × 10⁷ km. The curve is the geocentric path from 2049-01-17 to 2049-01-23, 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 |
|---|---|---|---|---|
| 2049-01-20 03:22:00 | Earth | 0.4235 AU | 164.8 LD | 20.9 km/s |
| 2050-01-28 10:46:00 | Earth | 0.2363 AU | 92.0 LD | 15.1 km/s |
| 2051-02-05 10:10:00 | Earth | 0.0508 AU | 19.8 LD | 9.3 km/s |
| 2052-01-30 21:52:00 | Earth | 0.1379 AU | 53.7 LD | 4.6 km/s |
| 2052-12-22 11:34:00 | Earth | 0.2432 AU | 94.7 LD | 6.5 km/s |
| 2053-04-19 02:25:00 | Earth | 0.2289 AU | 89.1 LD | 7.9 km/s |
| 2053-11-28 21:49:00 | Earth | 0.2835 AU | 110.3 LD | 7.3 km/s |
| 2054-05-21 23:58:00 | Earth | 0.2487 AU | 96.8 LD | 8.8 km/s |
| 2054-11-07 02:48:00 | Earth | 0.2818 AU | 109.7 LD | 7.2 km/s |
| 2055-06-24 14:14:00 | Earth | 0.2241 AU | 87.2 LD | 7.5 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