Jupiter and Saturnâs great conjunction, already underway, will reach its apex on Monday, Dec. 21.
âIâve been watching Jupiter and Saturn every day,â said Jorge Ballester, professor of physical sciences at Emporia State University. âItâs a real gradual change and it just happens that on Dec. 21, they are going to appear to be the closest together. And thatâs on the winter solstice, which is pretty cool.â
Ballester said Jupiter and Saturn come into conjunction â or pass each other every 20 years. Jupiter takes about 12 years to complete one revolution around the sun, while it takes Saturn 29 years to compete one revolution.