2 planets will align with the 'Earth-shining' moon on the summer solstice. Here's how to watch.

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Astronomical summer in the Northern Hemisphere begins with the closest alignments of Mars, Venus and the 'Earth-shining' crescent moon until 2028.

A woman with her back to the camera looks at the crescent moon and two planets through a telescope at sunset
Mars, Venus, and the shining crescent moon will align on the summer solstice (June 21) (Image credit: Getty)

The summer solstice on June 21 may be an important annual observance on Earth, but aside from the sun being its highest in the sky in the Northern Hemisphere, it's not typically a stargazing event. That changes in 2023 with the appearance in the solstice's evening twilight of Venus, Mars and a slim crescent moon in the western sky. 

The three celestial bodies won't appear this close together again to observers in North and South America until March 28, 2028, according to When The Curves Line Up. With alignments also appearing on the evenings before and after the solstice, it's a great week to be outside in twilight, with the added bonus of Da Vinci glow — or Earthshine, sunlight reflected by the Earth onto the dark lunar surface — visible on the waxing crescent moon. 

If you want to look for the slimmest crescent moon possible then use stargazing binoculars to find it in twilight low on the western horizon on Monday, June 19. It will be just over 3% illuminated, so may be difficult to spot in the bright post-sunset sky. 

Perhaps the best view of the three bodies comes on Wednesday, June 21 during the first twilight following the start of the  summer solstice, according to Timeanddate.com. The start of astronomical summer in the Northern Hemisphere will be marked by a right-angle triangle of Mars, Venus and a 13% illuminated crescent moon, though dim mars may be hard to spot without binoculars or a good small telescope. Look out for Da Vinci glow on the moon once again.

The final sight of the week occurs the following evening when, on Thursday, June 22, a 21% illuminated crescent moon will align once again with Mars and Venus, but this time from above the pair. The moon will also be close to Regulus in the constellation Leo.

All of these sights can be seen with the naked eye, but for a spectacular close-up of Da Vinci glow on the lunar surface a pair of stargazing binoculars or a telescope will help.

Jamie Carter
Jamie Carter
Live Science contributor

Jamie Carter is a Cardiff, U.K.-based freelance science journalist and a regular contributor to Live Science. He is the author of A Stargazing Program For Beginners and co-author of The Eclipse Effect, and leads international stargazing and eclipse-chasing tours. His work appears regularly in Space.com, Forbes, New Scientist, BBC Sky at Night, Sky & Telescope, and other major science and astronomy publications. He is also the editor of WhenIsTheNextEclipse.com.