Moon set to obscure Mars in a rare celestial event on June 30
A celestial spectacle awaits observers in specific regions of the world on June 30, 2025, as the moon is set to pass directly in front of Mars, resulting in a lunar occultation. This rare astronomical phenomenon, where one celestial body hides another from view, will be visible from 17:57 EDT on June 29 (21:57 GMT) to 22:35 EDT (02:35 GMT on June 30), as per In-The-Sky.org.
However, due to the Moon's proximity to Earth and the resulting significant parallax, the occultation itself will only be observable from a limited geographic area. Viewers in western Peru, Ecuador, western Colombia, and Clipperton Island are best positioned to witness Mars disappear and reappear from behind the lunar disk. The precise timings for visibility will vary by location, with Peru experiencing the occultation from 02:31–03:25 local time, Ecuador from 02:22–03:22 local time, Colombia from 02:39–03:05 local time, and Clipperton Islands from 01:43–02:48 local time.
For those outside this narrow band, a close conjunction between the Moon and Mars will still offer a compelling sight. While the complete occultation is geographically restricted, the two celestial bodies will appear remarkably close in the night sky for a much wider audience. Astronomers explain that the Moon's relatively close distance to Earth means its apparent position against the backdrop of stars varies considerably depending on an observer's precise location. This parallax effect can lead to a shift of up to two degrees, or four times the apparent diameter of a full moon, in the Moon's observed position when viewed from opposite sides of Earth. Consequently, an occultation visible from one part of the globe may appear as a near miss from another.
For astronomers and keen sky-watchers, Mars' position during the occultation is precisely charted. It will be located in the constellation Leo, with a Right Ascension of 10 hours, 35 minutes, and 50 seconds, and a Declination of 9 degrees, 56 minutes North. Mars will appear with a visual magnitude of 1.5, indicating a relatively bright object visible to the naked eye under clear, dark skies (lower magnitude numbers signify brighter objects). Its angular size, representing its apparent width in the sky, will be a mere 0 minutes and 4 seconds of arc, a testament to its vast distance from Earth.
Adding to its current celestial positioning, Mars officially entered the Spring Triangle on the night of June 19, and it's expected to continue traversing its lower edge until mid-September. Stargazers have been advised to direct their gaze westward in the nights following June 19, as Mars executed a notable celestial pass, sweeping past the bright star Regulus to join the Spring Triangle. This prominent asterism, clearly visible as spring transitions into summer in the northern hemisphere, is distinguished by three massive stars, each originating from a different constellation.
The Spring Triangle itself is comprised of the orange-hued Arcturus, located high above the southwestern horizon this month within the constellation Bootes, the herdsman. Directly below it, the blue-white Spica is visible, embedded in the constellation Virgo. Completing this cosmic formation near the western horizon is Regulus, often referred to as the "heart of the lion" in the constellation Leo.
