As June progresses, stargazers should look to the west on the nights following June 18 to witness a spectacular astronomical event. This is when Mars sweeps past the brilliant star Regulus, marking its entry into the Spring Triangle. This celestial formation consists of three prominent stars that shine brightly as spring transitions into summer in the northern hemisphere.
The Spring Triangle is formed by three massive stars, each belonging to a different constellation. These stars are Spica, Arcturus, and Regulus. The orange-hued star Arcturus can be seen high above the southwestern horizon shortly after sunset in June. It is surrounded by stars from the constellation Boötes, often referred to as the herdsman.
Directly below Arcturus is the blue-white star Spica, which is nestled within the constellation Virgo. Meanwhile, Regulus, often dubbed the "heart of the lion," resides in the constellation Leo, close to the western horizon. Together, these stars create a stunning cosmic triangle that captures the attention of amateur and seasoned astronomers alike.
Astute sky-watchers may have already noticed Mars drawing nearer to Regulus in the weeks leading up to June 18. Mars' orbit carries it along the ecliptic—the apparent path taken by the sun and planets in the night sky. On the evening of June 18, Mars will be located close to the upper left of Regulus, with less than 1 degree separating the two celestial bodies. For reference, 1 degree is roughly the width of your little fingertip when extended at arm’s length against the backdrop of the night sky.
The following night, Mars will officially enter the Spring Triangle, having crossed the imaginary line that connects Regulus and Arcturus. The Red Planet will continue to glide along the lower edge of this triangle, making its way beyond Spica by mid-September.
For those eager to explore the night sky, it’s a great time to consider investing in the best telescope or binocular deals available in 2025. These tools can significantly enhance your stargazing experience, allowing you to better observe celestial events like the conjunction of Mars and Regulus.
If you are new to stargazing, don’t miss our comprehensive list of the best smartphone stargazing apps. Many of these apps utilize augmented reality technology to assist users in navigating the vast array of stars and deep-sky objects visible from Earth. With the right tools and knowledge, you can fully immerse yourself in the wonders of our universe.
