Sky's Up Summer 2016 - Page 22

These craft range in distance from above Earth’s atmosphere to Sun-Earth L1 and on to the outskirts of the heliosphere (the volume of space controlled by the Sun’s magnetic field and solar wind). Most of them are observatories but some carry instruments to directly measure the environment they are in. It is notable that Voyager 1 ended its studies of the heliosphere in 2012 when it entered interstellar space. COURTESY OF NASA/JPL-Caltech It is escaping the Sun but This artist’s concept depicts NASA’s Voyager 1 spacecraft entering interstellar space. is still influenced by solar gravity while it sails through mission since 2004. The Huygens probe explored the interstellar medium. It will continue making Titan’s atmosphere and surface in January 2005 before measurements of this new environment succumbing to the extreme cold there. Cassini has By simply probably into the 2020s before its power wanes too much for instrument operations. continued its orbital tour of the Saturnian system and observing other Presently there are no spacecraft is scheduled to end in September 2017, diving through planets and operating at Mercury. Studies of Venus are the ring system three times before entering Saturn’s being carried out by the Japanese atmosphere. other planetary currently Uranus and Neptune have not been visited since Akatsuki orbiter. systems, we gain Robotic exploration of the Moon has been NASA’s Voyager 2 went by them in 1986 and 1989, respectively. But the outer Solar System hasn’t been perspective. By revived over the last 25 years. NASA’s entirely without monitors as the Voyagers cruised Lunar Reconnaissance Orbiter continues understanding monitoring our nearest neighbor in space through the heliosphere. In 2015, NASA’s New Horizons made a successful flyby of the Pluto system our neighbors, we even after additional missions from returning eye-popping images of a dwarf planet that is NASA and other nations have ended their better understand activities. apparently far more active than anyone would imagine for an object so far from the Sun. If additional funding The last of the terrestrial (rocky) our home. is granted, New Horiz