ocr: DWARFING EARTH, the head of a comet released by the nucleus as it is heated by may measure a million miles in diameter, the sun. A blue ion tail appears when and its tail can stretch al hundred million escaping gas molecules lose an electron miles. All this astronomical flamboyance to solar radiation and are carried off by comes from a solid nucleus of frozen. gas the solar: wind. and dust. As the nucleus rotates, jets of ejecta can A comet's dust tail gives off no light of swirl off, like sparkiers from a spinning pin- its own; its fiery brilliance is caused by wheel. The curved jets create w ...
