{"id":791199,"date":"2024-11-15T07:17:02","date_gmt":"2024-11-15T12:17:02","guid":{"rendered":"http:\/\/spaceweekly.com\/?p=791199"},"modified":"2024-11-15T07:17:02","modified_gmt":"2024-11-15T12:17:02","slug":"1st-intentional-signal-to-space-sent-by-arecibo-50-years-ago","status":"publish","type":"post","link":"https:\/\/spaceweekly.com\/?p=791199","title":{"rendered":"1st intentional signal to space sent by Arecibo 50 years ago"},"content":{"rendered":"
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\nOn November 16, 1974, the Arecibo Observatory beamed the 1st intentional signal to space. Image via Wikimedia Commons. Click here for an explanation of each part of the message.<\/figcaption><\/figure>\n
1st intentional signal to space in 1974<\/h3>\n
On November 16, 1974, astronomers used the Arecibo telescope in Puerto Rico to beam out the most powerful broadcast ever deliberately sent to space. They said the goal was to contact alien life. And some applauded it, but others didn\u2019t. On the plus side, it reminded people that Earth likely isn\u2019t the only planet in the Milky Way where intelligent life has evolved. But others felt \u2013 if alien civilizations do exist out there \u2013 we shouldn\u2019t call attention to ourselves. <\/p>\n
The 2025 EarthSky Lunar Calendar is now available! A unique and beautiful poster-sized calendar. Keep up with all phases of the moon every night of the year.<\/p>\n
The message in our signal to space<\/h3>\n
The message was designed by Cornell astronomy professor Frank Drake with input from other scientists including Carl Sagan. So, the final result was a simple and elegant broadcast. Basically, it consisted of a pattern of binary numbers. This message contained information about the basic chemicals of life and the structure of DNA. Plus, it included Earth\u2019s place in our solar system and even a stick figure of a human. <\/p>\nThe Arecibo radio telescope in Puerto Rico broadcast the 1st intentional radio signal into space in 1974. Image via Wikimedia Commons.<\/figcaption><\/figure>\n
Sending the Arecibo message<\/h3>\n
It took three minutes to send 1,679 bits of information, a snail\u2019s pace compared to modern computer modems. And according to the SETI Institute:<\/p>\n
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The broadcast was particularly powerful because it used Arecibo\u2019s megawatt transmitter attached to its 1,000 feet (305 meter) antenna. The latter concentrates the transmitter energy by beaming it into a very small patch of sky. The emission was equivalent to a 20 trillion-watt omnidirectional broadcast, and would be detectable by a SETI experiment just about anywhere in the galaxy, assuming a receiving antenna similar in size to Arecibo\u2019s.\n<\/p>\n<\/blockquote>\n
In fact, the 1974 signal went out in the direction of M13, a globular star cluster orbiting the center of our Milky Way galaxy. Basically, it was chosen because it\u2019s a large collection of stars and was available in the sky at the time and place of the ceremony.<\/p>\n
Also, globular star clusters are very far away. For instance, M13 is about 25,000 light-years from Earth. <\/p>\n
And now, the 1974 signal is 50 light-years away from us.<\/p>\n
By the way, the Arecibo radio telescope collapsed in 2020 when its 900-ton receiver platform came loose from its cables and fell onto the reflector dish more than 400 feet (120 meters) below. <\/p>\n
Read more: Video shows Arecibo telescope crash<\/p>\n
Bottom line: Iconic Arecibo telescope is no longer operational, but its legacy lives on. Fifty years ago, on November 16, 1974, Arecibo sent our first intentional signal to space. What do you think? Should we be advertising our presence in space?<\/p>\n
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Deborah Byrd<\/h4>\n
View Articles\n <\/p><\/div>\n
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About the Author:<\/h6>\n
Our Editor-in-Chief Deborah Byrd works to keep all the astronomy balls in the air between EarthSky’s website, YouTube page and social media platforms. She’s the primary editor of our popular daily newsletter and a frequent host of EarthSky livestreams. Deborah created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Prior to that, she had worked for the University of Texas McDonald Observatory since 1976, and created and produced their Star Date radio series. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. In 2020, she won the Education Prize from the American Astronomical Society, the largest organization of professional astronomers in North America. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.<\/p>\n<\/p><\/div>\n<\/p><\/div>\n
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