Fig. 5.1 Plasma tail of comet 1P/Halley from April 1986. This figure is an enhanced version of data
(LSPN 2671) in the International Halley Watch Large Scale Phenomenon Network archive
Table 5.1 Properties of the
solar wind from Hundhausen
in Kivelson and Russell
(1995)
Property
Value
Proton density
6.6 cm
À3
Electron density
7.1 cm
À3
He
2+ density
0.25 cm
À3
Flow speed
450 km s
À1
Proton temperature
1.2Á10
5 K
Electron temperature
1.4Á10
5 K
Dynamic pressure
2.6Á10
À9 Pa
Sound speed
60 km s
À1
Magnetic pressure
1.9Á10
À11 Pa
Proton gyroradius
80 km
Proton-proton collision time
4Á10
6 s
Electron-electron collision time
3Á10
5 s
Magnetic field strength
5 nT
400
5 The Plasma Environment