C/2018 C2 (Lemmon)
              < C 
 
            
          | Annual motion through the Solar System | |
| Discovery | |
|---|---|
| Discovered by | Mount Lemmon Srvy. | 
| Discovery site | Mount Lemmon Obs. | 
| Discovery date | 5 February 2018 (first observed only) | 
| Designations | |
| C/2018 C2 (Lemmon) | |
| ZC82561, A/2018 C2 | |
| hyperbolic comet | |
| Orbital characteristics | |
| Epoch 20 May 2018 (JD 2458258.5) | |
| Observation arc | 272 days | 
| Perihelion | 1.9565 AU | 
| −1083±3 AU | |
| Eccentricity | 1.0018 0.99924 (Barycentric epoch 2200) | 
| ≈ 130,000 years (outbound) | |
| -0.00036 | |
| 0° 0m 0.072s / day | |
| Inclination | 34.453° | 
| 91.14° | |
| 134.14° | |
| Earth MOID | 1.062 AU | 
| Jupiter MOID | 1.405 AU | 
| Physical characteristics | |
| Dimensions | 1.7–7.6 km (assumed) | 
| 19.0 (March 2018) | |
| 15.1±0.63 | |
C/2018 C2 (Lemmon) is a hyperbolic comet (previously classified as A/2018 C2, a hyperbolic asteroid). It was first observed on 5 February 2018 by the Mount Lemmon Survey conducted at the Mount Lemmon Observatory near Tucson, Arizona, in the United States. The discovery was announced on 4 March 2018 along with another hyperbolic object, A/2017 U7. Based on the absolute magnitude of 15.1, it may measure several kilometers in diameter. On 22 March 2018 it was determined to be a hyperbolic comet.