The notion of ions first arose in chemistry. In the 19th century it was well known that water in which salts were dissolved (or acids, or bases) conducted electricity, and that an electric current could separate such dissolved materials into their components. ... In 1898 Ernest Rutherford noted that the radiation seemed to contain two electrically charged components of opposite signs, steered by a magnet in opposite directions--positive "alpha rays" and negative "beta rays." ...
Titan . ... Hubble Space Telescope Images of Titan's surface . ... Later that year, it will release the European-built Huygens probe for a descent through Titan's atmosphere. ... This artist's rendering shows the European Space Agency's Huygens probe descending into the atmosphere of Saturn's moon Titan after being released by NASA's Cassini spacecraft. ... This artist's rendering shows the Huygens probe on the surface of Saturn's moon Titan after being released by NASA's Cassini spacecraft. ...