A 22-year-old man driving the moped died in the incident on Wood Street at the Junction with Horse Fair at 11:37pm.
His family are being supported by specialist officers.
The driver of the car failed to stop at the scene and while enquiries are ongoing, police are asking any witnesses to come forward.
Detectives are appealing for any witnesses or anyone with information, including dash cam footage, to call police on 101 quoting CAD 8352/07FEB26.
To remain 100 per cent anonymous, you can contact the independent charity Crimestoppers on 0800 555 111.
