Voyager 1 is officially the first human- made object to leave our solar system

     A spacecraft from Earth has left its cosmic backyard and taken its first steps in interstellar space. After streaking through space for almost 35 years, NASA's robotic Voyager 1 probe finally left the solar system in August 2012, in the Journal Science reports. Voyager has boldly gone where no probe has gone before marking one of the most significantt technological achievements in the annals of the history of Science, and as it enters interstellar space, it adds a new chapter in human scientific dreams and endeavors," NASA science  chief John Gruns feld said in hiss statement, "Perhaps some future deep-space explorers will catch up with Voyager, our first interstellar envoy, and reflect on how this intrepid spacecraft helped enable their future.
        Voyager 1 first detected the increased pressure of interstellar space on the heliosphere, the bubble of charged particles surrounding the sun that reaches far beyond the outer planets, in 2004. Scientists then ramped up their search for evidence of the spacecrafts interstellar arrival, knowing the data analysis and interpretation could take few months or years. Voyager 1 does not have a working plasma sensor, so scientists needed a different way to measure the spacecrafts plasma environment to make a definitive  determination of its location. A coronal mass ejection, or a massive burst of solar wind and magnetic fields, that erupted from the sun in March 2012 provided scientists the data they needed. When this unexpected gift from the sun eventually arrived at Voyager 1's location 13 months later, in April 2013. The plasma around the spacecraft began to vibrate like a violin string. On April 9, Voyager 1's plasma wave instrument detected the movement. Voyager 1 and its twin, voyager 2, were launched 16 days apart in 1977. Both spacecraft flew by Jupiter and Saturn. Voyager 2 also flew by Uranus and Neptune. Voyager 2, launched before voyager 1, is the longest continuously operated spacecraft. It is about 9.5 billion miles i.e 15 billion kilometres away from our sun. The cost of the Voyager 1 and Voyager 2 missions including launch, mission operations and the spacecrafts nuclear batteries, which were provided by the Department of energy.It is about $988 million through September.