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Ultra low frequency waves at the magnetic pile-up boundary of comet P/Halley

Glassmeier, K. -H.; Belmont, G.; Rème, H. +2 more

Around the magnetic pile-up boundary observed by Giotto at 135,000 km from the nucleus of comet Halley, plasma and magnetic features display evidence of ultra-low frequency modes. Outside the pile-up region, a large region is characterized by an anti-correlation between the electron plasma density and the magnetic field strength. The study of the …

Giotto extended mission

Schwehm, Gerhard

The navigation of the ESA spacecraft Giotto to its encounter with comet P/Halley on 14 March 1986 required just 10% of the fuel available. Although the spacecraft was damaged by dust impacts during its close flyby at the nucleus of P/Halley it was retargeted to return close to Earth to maintain the option to extend the mission to encounter another…

Plasma parameters near the comet Halley bow shock

Coates, A. J.; Neubauer, F. M.; Rème, H. +5 more

We analyse the available plasma data from the JPA, MAG and RPA instruments on Giotto for the inbound bow shock crossing at comet Halley. Proton, cometary heavy ion, electron and magnetic field data are combined on the inbound pass to yield the pressures of all the plasma components, and hence the characteristic plasma speeds and the Mach number of…

Cometary ion distributions near the pickup energy outside comet Halley's bow shock

Coates, A. J.; Neugebauer, M.; Gombosi, T. I. +2 more

This paper compares calculated and measured energy spectra of implanted H⁺ and O⁺ ions on the assumption that the pick-up geometry is quasi-parallel and about 1% of the waves generated by the cometary pickup process propagates backward (towards the comet). The model provides a good description of the implanted O⁺ a…