 Two other satellites made observations at the time of the impact : the Ulysses spacecraft , primarily designed for solar observations , was pointed towards Jupiter from its location 2 @.@ 6 AU away , and the distant Voyager 2 probe , some 44 AU from Jupiter and on its way out of the Solar System following its encounter with Neptune in 1989 , was programmed to look for radio emission in the 1 – 390 kHz range . 
