Mars will shine close to the blue star Spica at sunset on September 13, but a clear western horizon is needed to witness the view before both vanish swiftly.
As the sun sets, Mars will appear less than 10 degrees above the summer horizon. Spica will sparkle to its lower left among the stars of the Virgo constellation. For newcomers to stargazing, remember: a clenched fist at arm’s length equals about 10 degrees of sky, while three middle fingers span roughly 5 degrees.
Both Mars and Spica will sink below the horizon just over an hour after sunset. For the best chance of seeing them, find an elevated spot with a clear view of the western sky before the pair disappears.
The bright point of light we call Spica is actually a binary star system, its two stellar bodies producing a combined luminosity more than 12,000 times brighter than the sun. As the brightest jewel in Virgo, it lies 250 light-years away. Despite its brilliance, Spica does not rank among the top 10 brightest stars visible in Earth’s northern hemisphere.
Mars, on the other hand, owes its distinct red glow to oxidation that rusts the iron minerals found in its rocks, soil, and dust. In the coming weeks, the Red Planet will become harder to spot as it draws closer to the sun in Earth’s evening sky. This trend continues until its solar conjunction in January 2026, when Mars will cross behind the sun from Earth’s perspective, later reappearing as a bright red morning star in the predawn sky.
