We could use the same radio frequencies as the Arecibo message, but why not do something a little more dramatic?

FORBES

Arrange the message in 73 rows of 23 numbers, and you get a picture painted in bits. ( Click here to see the decoded Arecibo message.) It was a novel approach, but the message was hidden, and it depended on aliens making leaps of logic in order to decipher it.

FORBES