Know how to use "fewer" and "less"? Find out.
late 14c., marcien "of the planet Mars" (originally in reference to astrological influence), from Latin Martius "sacred to Mars; pertaining to the planet Mars," from Mars (genitive Martis). The noun meaning "an inhabitant of the planet Mars" is attested from 1883.
Packets that turn up unexpectedly on the wrong network because of bogus routing entries. Also a packet which has an altogether bogus (non-registered or ill-formed) internet address, such as the test loopback interface [127.0.0.1]. Such a packet will come back labelled with a source address that is clearly not of this earth. "The domain server is getting lots of packets from Mars. Does that gateway have a martian filter?"