| Object type | Apollo near-Earth asteroid, Mars-crosser; Q-type[1] |
|---|---|
| Discovered | May 10, 1991 by Eleanor F. Helin, Palomar[1] |
| Name | Built from Goldstone, Yevpatoria (Evpatoria) and Kashima[2] |
| Size | ≈ 0.53 km (JPL); ≈ 0.6 × 1.4 km in radar[1] |
| Density | 2.7 ± 0.5 g/cm³[2] |
| Mass | ≈ 2.1 × 10¹¹ kg[2] |
| Rotation period | ≈ 6.03 hours[1] |
| Distance from Sun | 0.943–4.01 AU[1] |
| Orbital period | ≈ 3.9 years[1] |
| Inclination | ≈ 2.3°[1] |
| Yarkovsky drift | 15 km off its gravity-only path, 1991–2003[2] |
| Next close passes | 0.05 AU in 2046; 0.10 AU in 2069[2] |
A name made of three observatories
In 1995 Golevka was observed by radar from three sites at once: Goldstone in California, the RT-70 dish at Evpatoria (Yevpatoria) in Ukraine, and Kashima in Japan. The name stitches together the first letters of each — proposed by the discoverer after a suggestion by Alexander Zaitsev.[2]
Found by a near-Earth asteroid pioneer
Golevka was discovered on 10 May 1991 by Eleanor F. Helin at Palomar.[1][2] Helin started the Palomar Planet-Crossing Asteroid Survey in the early 1970s and later led NASA’s Near-Earth Asteroid Tracking program; she discovered or co-discovered 903 asteroids.[4]
A shape that changes with your viewpoint
Golevka is small — JPL lists about 0.53 km, and radar gave about 0.6 × 1.4 km. Radar images revealed a strange, angular shape that looks quite different depending on the direction you view it from.[1][2]
Pushed by sunlight
A rotating asteroid warms in sunlight and re-emits that heat a little later, on a different side. The emitted infrared carries momentum, producing a tiny steady force — the Yarkovsky effect.[3]
Golevka is where it was first measured. Between 1991 and 2003, precise radar tracking showed it had drifted 15 km from where gravity alone predicted.[2][3] The force is estimated at just 0.25 newtons, yet over millions of years such pushes can move asteroids from the main belt into the inner Solar System.[3]
Orbit
Golevka’s stretched orbit runs from just inside Earth’s distance (0.94 AU) out to about 4 AU every 3.9 years.[1] Its orbit is strikingly similar to that of 4179 Toutatis.[2] It will pass 0.05 AU from Earth in 2046 and 0.10 AU in 2069, but its collision chance with any planet is negligible for at least nine centuries.[2]
Science you can do at home
The Yarkovsky effect comes down to heat, light and spin — all things kids can experiment with. Our science kit picker suggests hands-on kits by age and interest.
Read more
Golevka and the first measurement of the Yarkovsky effect
How twelve years of radar tracking caught sunlight nudging a half-kilometre asteroid by 15 km.
Read →Go-Lev-Ka: an asteroid named by radar
In 1995, three radar observatories on three continents studied one small asteroid — and gave it a name.
Read →Eleanor “Glo” Helin, asteroid hunter
The JPL astronomer who found Golevka spent three decades searching for near-Earth asteroids.
Read →Sources
- Small-Body Database Lookup: 6489 Golevka — NASA JPL Solar System Dynamics
- 6489 Golevka — Wikipedia
- Yarkovsky effect — Wikipedia
- Eleanor F. Helin — Wikipedia
- Goldstone Deep Space Communications Complex — Wikipedia
- Arecibo Telescope — Wikipedia
- Planetary Fact Sheet (orbit comparison) — NASA NSSDCA
Figures are rounded; where sources differ we note it. Spotted an error? Tell us.