... Comet Animation . ... Comet structures are diverse and very dynamic, but they all develop a surrounding cloud of diffuse material, called a coma, that usually grows in size and brightness as the comet approaches the Sun. ... As comets approach the Sun they develop enormous tails of luminous material that extend for millions of kilometers from the head, away from the Sun. ... The evaporated molecules boil off and carry small solid particles with them, forming the comet's coma of gas and dust. ...

Hubble Observations Shed New Light on Jupiter Collision . Was it a comet or an asteroid? ... Their initial findings, combined with results from other space-borne and ground-based telescopes, shed new light on Jupiter's atmospheric winds, its immense magnetic field, the mysterious dark debris from the impacts, and the composition of the doomed comet itself. ... Hubble's ultraviolet observations show the motion of very fine impact debris particles now suspended high in Jupiter's atmosphere. ...

... Hiorter and Celsius note that the polar aurora is accompanied by a disturbance of the magnetic needle. ... Richard Carrington in England observes a violent and rapid eruption near a sunspot; 17 hours later a large magnetic storm begins. ... Using it he observes a solar flare and confirms the connection between flares and magnetic storms. ... Explorer 1, launched by the US January 31, observes the radiation belt; Explorer 3, launched in March, comes up with the first clear evidence for its existence....