On January 7,1610, Galileo, using his primitive telescope, discovered the four major moons of Jupiter: Io, Europa, Ganymede and Callisto.
(Galileo; discovered; the four major moons of Jupiter; T:On January 7,1610) Context(Galileo discovered,List([19, 69))):(Galileo; discovered the four major moons of Jupiter using; his primitive telescope)
Galileo discovered,List([19, 69))
Galileo Galileo
discovered discovered the four major moons of Jupiter using
the four major moons of Jupiter T:On January 7,1610
his primitive telescope