
In 1974, the Arecibo Observatory made history by beaming the most powerful radio message into deep space ever made.
In 1974, the Arecibo Observatory made history by beaming the most powerful radio message into deep space ever made.
If extraterrestrial intelligence exists somewhere in our galaxy, a new MIT study proposes that laser technology on Earth could, in principle, be fashioned into something of a planetary porch light -- a beacon strong enough to attract attention from as far as 20,000 light-years away.