NASA announced Thursday that the Voyager 1 spacecraft crossed the boundary between our sun's influence into interstellar space. The spacecraft is still on duty, still sending back data. Even at the speed of light, it takes nearly 19 hours to cross the 11.7 billion miles. The signal is very weak as it reaches Earth. For comparison, Voyager 1's signals are 10 quadrillionth the 1 watt of energy cellphones operate on.

Scientists expect Voyager to continue functioning for many years. On-board memory (a single 8-track tape recorder, remember this was launched in 1977) is expected to last another two years. Mission managers aren't even planning to begin shutting down science instruments until 2020 and anticipate another 5-10 years of operations in a reduced power consumption mode.

Even after the final instrument is powered down, a project led by the late astronomer Carl Sagan will ensure that Voyager 1's mission continues as a "bottle into the cosmic ocean."

A team led by Sagan created "Messages from Earth," a recording of images, music and other sounds of Earth including greetings in 55 languages. The resulting 12-inch, gold-plated (for longevity) copper record was mounted on the side of Voyager 1 and 2 along with instructions and a stylus. Instructions show how to playback the sounds on the record and decode the 115 images of Earth and its inhabitants. A map to our solar system using pulsars as guideposts is also included with the instructions. An atomic clock of sorts was included with a small disc of an ultra-pure source of Uranium-238, half of which will decay over the next 4.51 billion years.

The project originally envisioned United Nations members recording greetings in their native languages. However, the concept of "short greetings" was lost on the delegates as each either made a speech or recited poetry from their homeland.

Sagan turned to the sizable linguistics department at the university where he taught astronomy. On the morning of June 8, 1977, a group grad students arrived on a few hours notice at Cornell University's administration building for a very unique recording session.

The only instruction given to the collection of students was to come up with a "greeting to the universe" in their language and to write the greeting and an English translation. Sagan explained that recordings would placed aboard a spacecraft and participants were asked to sign a release that granted NASA the right to use the session "throughout the world and extraterrestially."

The Portuguese greeting was provided by Janet Sternberg, a graduate student in linguistics and a teaching assistant in Portuguese. She was third to record and had only minutes to think of how she would represent the planet's Portuguese speakers, a heavy responsibility for a 23-year-old. In just a few words, she spoke for Rio de Janeiro where she grew up, Brazil as a whole and for Portugal and numerous African nations where the language is spoken.

I talked with Dr. Sternberg about her experiences that day. She recalled the day fondly, speaking of a sense of camaraderie that quickly developed. She also shared her greatest concern then and now, "What will other Portuguese of the world think of what I'm saying?"

Most greetings expressed best wishes.

The Gujarati reached out with "Greetings from a human being of the Earth. Please contact."

The Amoy reflected common greetings of that culture: "Friends of space, how are you all? Have you eaten yet?"

The Swedish greeting was a mini-resume: "Greetings from a computer programmer in the little university town of Ithaca on the planet Earth."

The last greeting was recorded in English, by Carl Sagan's 5-year old son Nick: "Hello from the children of planet Earth."

Today Nick Sagan is a science-fiction novelist and screenwriter.

As Sternberg listened to her colleague David Owen record "May all be well" in Sumerian and Frederick Ahl record "We come in friendship to those who are friends," she thought of cold war gripping the United States and considered what Brazilians would most like to offer to the world and beyond. When her turn came, she recorded "Paz e felicidade a todos (Peace and happiness to everyone)."

Sternberg got her answer about what Portuguese speaking people thought when years later the Brazilian news magazine show "Fantástico" interviewed her. According to Sternberg, Fantástico's hosts were moved by her words and she "heard from people not heard from in years."

A copy of the golden record is on display at the Smithsonian's National Air and Space Museum, in Washington, DC. The images, music, sounds and greetings are also available on NASA's voyager website.

Tony Rice is a volunteer in the NASA/JPL Solar System Ambassador program and software engineer at Cisco Systems. You can follow him on twitter @rtphokie.