Jupiter to several seconds, and short bursts (or S-bursts) that had a duration of less than a hundredth of a second. Scientists discovered that there were three forms of radio signals transmitted from Jupiter. Since 1973 a number of automated spacecraft have visited Jupiter, most notably the "Pioneer 10" space probe, the first spacecraft to get close enough to Jupiter to send back revelations about the properties and phenomena of the Solar System's largest planet. Flights to other planets within the Solar System are accomplished at a cost in energy, which is described by the net change in velocity of the
Mercury (planet) place it onto the correct trajectory to reach an orbit around Mercury. A first fly-by of Mercury occurred on January 14, 2008, a second on October 6, 2008, and a third on September 29, 2009. Most of the hemisphere not imaged by was mapped during these fly-bys. The probe successfully entered an elliptical orbit around the planet on March 18, 2011. The first orbital image of Mercury was obtained on March 29, 2011. The probe finished a one-year mapping mission, and then entered a one-year extended mission into 2013. In addition to continued observations and mapping of Mercury, "MESSENGER" observed