Scientists had observed that comet tails pointed away from the sun although comets or other material had not been seen to originate from the sun. Spacecraft later detected winds of charged particles generated from the sun. The solar wind is a stream of ionised particles originating from the sun in all directions. The solar wind consists of a mixture of electrons, protons and some atomic nuclei, which is a plasma, or good conductor of electricity. The solar wind usually travels at speeds of around four hundred kilometres per second although it can travel up to speeds of seven hundred kilometres per second. The solar wind is caused by the outer atmosphere of the sun, called the corona that extends into space. The top part of the corona continually flows into space so that the sun does not eventually find its...