There will be a three-planet conjunction throughout the week, involving Mercury, Venus, and Jupiter. The closest approach, however, was on Sunday night.
The three planets shined together in a formation in the western sky, which is known as a conjunction, according to Space.com.
“Triple conjunctions of planets are fairly rare,” astronomer Tony Phillips said, according to the website. “The last time it happened was in May 2011 and it won’t happen again until October 2015.”
The website noted that the Mercury, Venus, and Jupiter are the three brightest planets in the night sky in May.
As University of Guam Planetarium Coordinator Pam Eastlick points out, the conjunction on Sunday night was its closest approach to Earth. However, “the configuration has been changing from night to night and will continue to change for the rest of the week,” Eastlick told the Pacific News Center.
“It’s easy to tell which one is which because Venus is incredibly bright. So when you look at the three, the triangle of objects tonight, Venus is the really bright one. The second brightest one is Jupiter and the one that’s the third brightest, that’s Mercury,” she added.