Selam (moon)
| Discovery | |
|---|---|
| Discovered by | Lucy (spacecraft) |
| Discovery date | 1 November 2023 |
| Designations | |
| Pronunciation | /səˈlɑːm/ |
| Dinkinesh I | |
| Orbital characteristics | |
| 3.11±0.05 km | |
| Eccentricity | ≈0 |
| 52.67±0.04 h | |
| Satellite of | Dinkinesh |
| Physical characteristics | |
| Dimensions |
|
| |
| Mass | 2.8×1010 kg |
| 52.44±0.14 h (likely synchronous) | |
Selam (formal designation Dinkinesh I) is a contact binary moon of the main belt asteroid 152830 Dinkinesh. It was discovered by NASA's Lucy space probe when it flew past Dinkinesh on 1 November 2023. The moon consists of two conjoined lobes of similar size, each around 220 metres (720 ft) in diameter.
Together, Dinkinesh and Selam form a binary asteroid system. Dinkinesh is the second binary main-belt asteroid explored by spacecraft, after 243 Ida by Galileo in 1993. The Dinkinesh binary system resembles the 65803 Didymos near-Earth asteroid binary system in size and composition, but differs in location from the Sun, which allows scientists to compare the nature of binary asteroids in different environments.