Mercury reaches its greatest elongation, farthest from the sun, on March 7-8, 2025.Visible in the western sky after sunset, Mercury will be about 18 degrees from the sun at its greatest elongation.Mercury, shining at -0.4 magnitude, will appear brighter than most stars during this time.It will rapidly fade after greatest elongation as it moves behind Earth in its orbit.Mercury will be approximately 47% illuminated and 7.3 arcseconds across when viewed through a telescope.During this elongation, Mercury will be in front of the constellation Pisces.Mercury's visibility is tied to the sun, never venturing far above the horizon.Venus and Mercury will be close in the sky in March, both planets disappearing in bright twilight by mid-March.Brilliant Venus will emerge in the morning sky in April, with both planets having upcoming significant events in 2025.Mercury's elongations vary throughout the year, with the best evening apparition for the Northern Hemisphere in March.