Rotational work is common for the field operator, often involving eight days of 10-hour shifts followed by six days off. Unlike plant operators, field operators usually work days. Evening call-outs can occur if maintenance or production issues arise at a well site the operator covers.
Before the advent of telescopic photography, eight moons of Saturn were discovered by direct observation using optical telescopes. Saturn's largest moon, Titan, was discovered in 1655 by Christiaan Huygens using a 57-millimeter (2.2 in) objective lens on a refracting telescope of his own design. Tethys, Dione, Rhea and Iapetus (the  Sidera Lodoicea ) were discovered between 1671 and 1684 by Giovanni Domenico Cassini.
So far astronomers have discovered 62 moons orbiting Saturn. However, only 53 of these have official names and only 13 are larger than 50 km (31 mi.) in diameter. The largest moon of Saturn is Titan and it is also the second largest moon in the solar system after Ganymede (a moon of Jupiter).