TOKYO -- Jupiter and Saturn are nearing their first "super-close approach" in 397 years, with the rare rendezvous visible in the southwestern sky after sunset in Japan.
Along the riverbed of the Arakawa River in Tokyo's Katsushika Ward on the evening of Dec. 17, Jupiter and Saturn appeared lined up near Tokyo Skytree in Sumida Ward while a thin crescent moon shined beautifully nearby.
Jupiter orbits the Sun about every 12 years, and Saturn around every 29.5 years, and when viewed from Earth, the planets appear to line up almost every 20 years. According to the National Astronomical Observatory of Japan, both planets will approach each other by about a quarter of the moon's diameter at around 3 a.m. on Dec. 22.
The last time the planets came so close was in July 1623, and the next time will be 60 years from now. In Japan on the evening of Dec. 21 and 22, it's projected it will be possible to see the two planets shining side by side with the naked eye or with binoculars.
The brightness of celestial objects is measured in magnitude, with lower numbers indicating a brighter object. Jupiter's magnitude was measured at minus 2, and Saturn at 0.6.
(Japanese original by Koichiro Tezuka, Photo Group)