In 1974, scientists sent mankind’s first, three-minute long interstellar radio message – the Arecibo Message. The message was sent from the Arecibo Observatory in Puerto Rico.
Their three-minute radio message—a series of exactly 1,679 binary digits (a multiple of two prime numbers) which could be arranged in a grid 73 rows by 23 columns—was aimed at a cluster of stars 25,000 light years away from earth, Google wrote.
The message was broadcast into space a single time via frequency modulated radio waves.
Astronomer and astrophysicist Frank Drake from Cornell University wrote the message with the help from American astronomer Carl Sagan, among others.
Since the Arecibo Message will take roughly 25,000 years to reach its intended destination (a group of 300,000 stars in the constellation Hercules known as M13), humankind will have to wait a long time for an answer.
In the 44 years since it was first transmitted, the message has traveled only 259 trillion miles, only a tiny fraction of the 146,965,638,531,210,240 or so miles to its final destination, Google wrote.