NASA's Voyager 1 spacecraft is about to leave the sun's territory to enter the inter-stellar space. NASA's twin spacecrafts Voyager 1 and Cassini reached edge of the solar system sooner than expected which means the boundary of solar system is smaller than what scientists had earlier speculated.

Voyager 1's exit is expected to give astrophysicists new data accounts of life outside the solar system.

The spacecraft was launched 34 years ago and is now cruising through space some 10.8 billion miles from the sun. Voyager 1 has crossed into an area where the velocity of the hot ionized gas, or plasma, emanating directly from the sun has slowed from 150,000 miles an hour down to zero.

These calculations show we're getting close, but how close? asks Ed Stone, a Voyager project scientist based at Pasadena's California Institute of Technology. That's what we don't know, but Voyager 1 speeds outward a billion miles every three years, so we may not have long to wait.

Incoming data from the two spaceships will be examined until they get confirmation that the frontier has actually been crossed. Once solar system is confirmed to be crossed scientists will know just how large an area the Solar System covers. Upon entering the interstellar space Voyager 1 will be the first of Earth's spacecraft to leave the sun's territory.

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