I have been somewhat obsessed with space lately. I also recently learned that there are spacecraft outside of our solar system, which for some reason just seems really cool to me. In September of 2013 Voyager 1 officially left the heliosphere, which is the area in space dominated by solar winds and charged particles from the sun and extends about twice the distance from Pluto as Pluto is from the sun. The deep space probe Voyager 2 was launched on August 20th, 1977 and Voyager 1 was launched two weeks later on September 5th. Voyager 2 has yet to breach into interstellar space. Despite the fact that it was launched earlier, because it is traveling slower than Voyager 1 at some 15 Km/s relative to the sun compared to 1's 17 Km/s. The original purpose of the Voyager mission was to explore the outer planets of the solar system. After providing great data on Saturn, Neptune and Pluto in the 80's the mission was extended to gather data on interstellar space, space dominated by radiation from stars other than our sun. Both probes are still gathering and sending data back to the earth, which takes about 17 hours to travel from the probe's transmitter to NASA's Deep Space Network, a global array of giant radio communication dishes. The probes will be able to record and transmit data until 2025 when their nuclear batteries are expected to die and then they will sail though the cosmos for the rest of eternity, lonely travelers among unknown worlds.