Forty-four years ago today, a group of scientists gathered at the Arecibo Observatory amidst the tropical forests of Puerto Rico to attempt humankind’s first communication with intelligent life beyond our own planet. 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.

This historic transmission was intended to demonstrate the capabilities of Arecibo’s recently upgraded radio telescope, whose 1000-foot-diameter dish made it the largest and most powerful in the world at the time. "It was strictly a symbolic event, to show that we could do it," said Donald Campbell, Cornell University professor of astronomy, who was a research associate at the Arecibo Observatory at the time. Nevertheless some of those present were moved to tears.

The message itself was devised by a team of researchers from Cornell University led by Dr. Frank Drake—the astronomer and astrophysicist responsible for the Drake Equation, a means of estimating the number of planets hosting extraterrestrial life within the Milky Way galaxy. ‘‘What could we do that would be spectacular?’’ Drake recalled thinking. “We could send a message!’’

Written with the assistance of Carl Sagan, the message itself could be arranged in a rectangular grid of 0s and 1s to form a pictograph representing some fundamental facts of mathematics, human DNA, planet earth’s place in the solar system, and a picture of a human-like figure as well as an image of the telescope itself.

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. How long? 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. During that same time, our understanding of the cosmos has advanced by leaps and bounds, raising hopes that someone may be out there, listening.

The subject of today’s Doodle lends itself to so many possibilities. Earlier concepts experimented with depicting the recipients of the Arecibo Message and their reactions.

Doodler, Gerben Steenks.