Did you know that there is a greeting in the Urdu language floating around in space currently, some 19 billion kilometers from Earth?

How did it get there, and for whom is it intended are the two questions that naturally follow.

In 1977, Nasa launched a spacecraft called the ‘Voyager’, which was equipped with scientific instruments to increase our understanding of outer planets, the solar system, and the worlds beyond it.

This spacecraft is the first of any kind to capture breathtaking views of planets Jupiter, Saturn, Uranus and Neptune.

After 38 years of sailing through space and traveling a distance of some 19 billion kilometers, the Voyager has now exited our solar system and entered the interstellar space.

However, when this machine was being designed, a pertinent question arose; what if other intelligent extraterrestrial life forms were to stumble upon it? And if they did, how would they know it was sent from Earth?

As a solution to this problem, a ‘Golden Record’ — containing pieces of music, pictures and various sounds from all over the world, including greetings in 55 different languages — was fixed on the Voyager.

Resultantly, when and if, other intelligent life forms do intercept the spacecraft, they would know its origin, and with it, about us.

Dr. Salman Hameed from Hampshire College, USA, explains this intriguing concept and the story behind the Golden Record in the video above.

This video is a part of a series titled ‘Science Ka Adda’, which is aimed at enhancing public understanding of science.