Voyager 1 reaches the edges of the solar system

By Melissa Bell

It is a space mission 33 years in the making: The Voyager 1 spacecraft will cross a boundary not yet crossed before. It will leave our solar system and enter interstellar space.

Launched in 1977, the unmanned ship is about 10.8 billion miles away from the sun, in an area of the solar system called the heliosheath. The heliosheath is the final area of the solar system where the sun's wind blows:

NASA reports:

Voyager 1 has crossed into an area where the velocity of the hot ionized gas, or plasma, emanating directly outward from the sun has slowed to zero... The event is a major milestone in Voyager 1's passage through the heliosheath, the turbulent outer shell of the sun's sphere of influence, and the spacecraft's upcoming departure from our solar system.

Again, though, we're talking about NASA time. So the final miles the Voyager needs to cross before it reaches that whole new world will probably take four years, researchers estimate.

Though the primary purpose of the Voyager is to collect data, it does have an onboard message if any aliens should come across it. The Voyager Golden Record has "115 images and a variety of natural sounds, such as those made by surf, wind and thunder, birds, whales, and other animals... musical selections from different cultures and eras, and spoken greetings from Earth-people in fifty-five languages."

Update: This is so cool. This Web site has some of the sound excerpts from the Golden Record. Listen to what sounds the 1977 NASA thought should be preserved to encapsulate humanity and Earth.

This post was updated at 12:30 p.m.