Five planets will line up below the crescent moon in a rare “planetary parade” most clearly visible in Massachusetts on Wednesday night, astronomers said.
Most of the celestial display — featuring Jupiter, Mercury, Venus, Uranus, and Mars — can be seen for two weeks, though it will gradually get harder to see all the planets each night, said Silas Laycock, an astronomer and associate professor at the University of Massachusetts Lowell.
The planetary alignment offers a unique glimpse into the mechanics of the solar system, Laycock said.
“You can really get out there and see how the solar system works,” Laycock said. “You’ll be able to see five celestial bodies, and one night to the next track how they move.”
The best time to see the planetary parade is generally Monday and Tuesday, Laycock said. But due to heavy clouds, it will be difficult, if not impossible, to view it in Massachusetts on those days, according to the National Weather Service. Most of the planets will likely still be visible Wednesday night, Laycock said.
To spot the alignment, seek a clear view of the western horizon at sunset, Laycock said. It’ll be easiest to find Venus, which shines the brightest.
“Find Venus and then track down toward where the sun has just set,” Laycock said. “In that space, look about a hands width over the horizon for a little bright dot, which will be Jupiter. Squint your eyes and very, very close to Jupiter will be Mercury.”
It will require binoculars to see Uranus, the dimmest planet, which will fall near Venus. But the rest of the display should be visible to the naked eye, weather permitting, Laycock said.
The planets will fall roughly in a straight, vertical line descending from the moon, according to Laycock.
“It’s kind of neat to see all these celestial bodies at the same time, in line, and see it at sunset,” he said.
Planetary alignments with two or three celestial bodies are relatively common, Laycock said. They occur when planets’ orbits are in conjunction so they gather on the same side of the sun.
But it’s rare to see five planets gleaming in just one night.
“If you miss it [Monday], or you just don’t manage to see them, I would say keep looking over the next few nights,” Laycock said. “Although Jupiter will be hiding behind the sun for the next month, Mercury will get higher and higher and actually be easier to see.”
Either way, the planetary parade gives onlookers the chance to navigate the night sky and the hurdles that come with stargazing, he said.
“It’s a fun challenge, like, ‘How many do you actually manage to see?’” Laycock said.
Kate Armanini can be reached at kate.armanini@globe.com. Follow her on Twitter @KateArmanini.