THE Solar System鈥檚 magnetic field has finally been traced. Swirling lines, recorded by the space probe Ulysses, show how the magnetic field lines emanating from the Sun鈥檚 surface are dragged round as the Sun rotates. The magnetic field鈥檚 spiral shape was first predicted in 1958. The probe鈥檚 measurements are a 鈥渄irect unequivocal confirmation鈥� of that prediction, say scientists from the aerospace company STX Hughes and NASA鈥檚 Goddard Space Flight Center, in this week鈥檚 Science.
The magnetic field lines form highways along which electrons travel after being ejected from the Sun. Ulysses tracked the electromagnetic radiation given off by these electrons 鈥� the white dots. The probe enjoyed a bird鈥檚-eye view of the Solar System as it passed high above the Sun鈥檚 geographical pole.