 | |
| Discovery[1] | |
|---|---|
| Discovered by | Spacewatch |
| Discovery site | Kitt Peak National Obs. |
| Discovery date | 3 February 1994 |
| Designations | |
| (136617) 1994 CC | |
| 1994 CC | |
| NEO · PHA · Apollo[1][2] Earth-crosser | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 28.45 yr (10,391 days) |
| Aphelion | 2.3206AU |
| Perihelion | 0.9551 AU |
| 1.6378 AU | |
| Eccentricity | 0.4169 |
| 2.10yr (766 days) | |
| 321.07° | |
| 0° 28m 12.72s / day | |
| Inclination | 4.6806° |
| 268.55° | |
| 24.842° | |
| Knownsatellites | 2[3] |
| Earth MOID | 0.0157 AU · 6.1LD |
| Physical characteristics | |
| 0.62±0.06 km[4] 0.650 km[3] | |
| 2.3886±0.0001 h[3] 2.38860±0.00009h[4] | |
| 0.3821(derived)[5] | |
| Sq[4] · Sa[6] · S[5][7] | |
| 17.00[7] · 17.7[1][5] · 18.12±0.84[8] | |
(136617) 1994 CC is a sub-kilometertriple asteroid,[3] classified as anear-Earth object andpotentially hazardous asteroid of theApollo group.
1994 CC was discovered bySpacewatch'sJim Scotti atKitt Peak National Observatory on 3 February 1994.[2] In June 2009 it was shown to be a triple system, i.e. the largest body is orbited by twosatellites; only about one percent (1%) of near-Earth asteroids observed by a radar are found to be triple systems such as this one.[9] The only other unambiguously identified triple asteroids in the near-Earth population are(153591) 2001 SN263, which was discovered to be a triple system in 2008, and3122 Florence, which was found to be a triple system in 2017.
A team of NASA'sJet Propulsion Laboratory (JPL) (Pasadena, California) scientists led byMarina Brozovic andLance Benner, made the discovery usingradar imaging atNASA'sGoldstone Solar System Radar on June 12 and June 14, 2009. They showed that the near-Earth asteroid1994 CC is a triple system, which encounteredEarth within 2.52 million kilometers on June 10, 2009. This relatively close approach to Earth made the discovery possible, as before the approach, scientists knew very little about this asteroid. In fact,1994 CC is only the second triple system known in thenear-Earth objects population.[9]
1994 CC consists of a central object about 700 meters in diameter that has twomoons revolving around it. Scientists' preliminary analysis of the system suggests that the moons are at least 50 meters in diameter. In a similar study, the radar observations atArecibo Observatory inPuerto Rico, led by theMike Nolan, also confirmed the detection of all three objects. The scientists plan to use the combined observations from the Goldstone and Arecibo observatories to study1994 CC's orbital and physical properties further.[9]
The next similar Earth flyby for the asteroid1994 CC will happen in 2074 when the triple system is projected to fly past Earth at a distance of 2.5 million kilometers.[9]
The orbital properties of the satellites are listed in this table.[10] The orbital planes of both satellites are inclined relative to each other, by approximately 16°. Such a large inclination is suggestive of past evolutionary events (e.g. close encounter with a terrestrial planet, mean-motion resonance crossing) that may have excited their orbits from a coplanar configuration to an inclined state.
| Name | Mass [109 kg] | Semi-major axis [km] | Orbital period [days] | Eccentricity | Inclination (relative to asteroid) [°] |
|---|---|---|---|---|---|
| Beta | ~6 | 1.7 | 1.243 | 0.002 | 95 |
| Gamma | ~1 | 6.1 | 8.376 | 0.192 | 79 |
Thisminor planet wasnumbered by theMinor Planet Center on 5 December 2006.[11] As of 2019[update], it has not beennamed.[2]
Radar imaging at NASA's Goldstone Solar System Radar [..] revealed that near-Earth asteroid 1994 CC is a triple system
