Deep Space 1 at comet 19P/Borrelly: Magnetic field and plasma observations

► Magnetic field measurements during the Deep Space 1 flyby at Comet Borrelly. ► Detection of cometary bow shock at 147 000 km distance from the nucleus. ► Turbulence due to ion pickup detected in the sheath region and upstream of shock. ► A peak field of 83 nT was measured asymmetric to the closest approach (5 min later). ► The Borrelly results are compared with other cometary flyby results.