The calculated distance (air line) between Bochum-Hordel and Ottignies is approximately 127 miles respectively 205 kilometers.
By car or train, the actual journey to Ottignies is certainly longer, as only the direct route (as the crow flies) between Bochum-Hordel and Ottignies has been calculated here.
Air line (approximately)
205 kilometers
110 nautical miles