Originally posted in the easter-eggs channel; an identical version was later reposted when official-art was started.
The image was immediately identified to be Galileo Galilei.
The depiction of a shooting star or comet in the lens of the telescope and an eye from Rob spurred hunters back to 1064 Aethusa, an asteroid which had already been found to share a name with the woman of Greek myth. This quickly led to the discovery that 1064 (num1064) was the password for T1A.