Page 71 - BBC Sky at Night - September 2017 UK
P. 71

VOYAGER AT 40 SEPTEMBER 71


















           14 FEBRUARY 1990     17 FEBRUARY 1998    17 DECEMBER 2004    30 AUGUST 2007       25 AUGUST 2012
           Voyager 1 takes the Pale   Voyager 1 becomes the   Voyager 1 passes the   Voyager 2 passes the   Voyager 1 crosses the
           Blue Dot image of Earth   most distant human-  termination shock and   termination shock and   heliopause and enters
           from 6 billion km away  made object in space  enters the heliosheath    enters the heliosheath    interstellar space




                         From 33.9 million km, Voyager 2
                          saw the famous rings and even
                               cloud patterns on Saturn
















                                                   ! Surprisingly, Uranus was seen to be featureless when Voyager 2 arrived (left)
                                                   but moons like Ariel (above right) and Miranda (top right) revealed wild and varied
                                                   surface features pointing to pasts marked by dramatic geological activity

                                                                         Icy world Enceladus seen
                                                                         here by Voyager 2,
                                                                         is one of the most
                                                                         reflective bodies
                                                                         in the Solar
                                                                         System
                                       Spokes were
                                  revealed in Saturn’s
                                  complex ring system













         storms, including the Great Dark Spot, and 1,600km/h   ! Titan’s atmosphere is so   sunlight – the now famous ‘Pale Blue Dot’ image
         winds – the strongest on any planet. It imaged eight   thick that the Voyager   of Earth. Carolyn Porco planned and executed this
         of Neptune’s moons, discovering five of them and   could not see down to the   Family Portrait alongside Carl Sagan. “As soon
         saw active geysers on the largest moon, Triton.  surface (top) but pearly   as I joined the Voyager imaging team in fall 1983,
                                                   white Dione was seen   the idea arose in my mind to take an image of the
         One last glimpse                          glimmering in front of   planets, but especially Earth, as they would be seen
                                                   Saturn’s clouds (bottom)
         On Valentine’s Day 1990, Voyager 1 took the final               from far away, to force that ‘reckoning’ that comes
         pictures of the mission. Turning its camera back               from seeing our cosmic place as it really
         towards the Sun, from about 6 billion km away,                 is ... alone and isolated,” she says.
         it took images of Neptune, Uranus, Saturn,                       This marked the end of the Voyagers’ planetary
         Jupiter, Venus and – suspended in a beam of                    explorations – the Grand Tour, as it’s known – and >


                                                                                      skyatnightmagazine.com 2017
   66   67   68   69   70   71   72   73   74   75   76