Comparing this apparition to the one in 2018, Mars will appear 1.7" smaller, but it will stand 31° higher in the sky. An object’s altitude is an important consideration for viewing because the less air you look through, the better the image will be. If you observe Mars at opposition from a site at 40° north latitude, its altitude at midnight (when it’s highest in the south) will be a worthy 55°. If your observing location is more northerly, Mars will lie 1° lower for each degree of latitude. But south of 40°, it will appear 1° higher per degree of latitude. I look forward to seeing it standing 63° high in the south from my location in Tucson.
Mars also will appear 0.2 magnitude fainter than it did two years ago. That said, it still will blaze at magnitude –2.6 from October 5-16. In fact, it will be brighter than magnitude –2.0 from September 7 through November 6; and brighter than Sirius (Alpha [a] Canis Majoris), which is the brightest star at magnitude –1.46, from August 17 through November 20.
Throughout this entire period, Mars will appear within the boundaries of the constellation Pisces the Fish. During most of its orbit, Mars moves eastward through the backdrop of stars. But when Earth overtakes and passes it, the Red Planet appears to travel westward — movement that astronomers refer to as retrograde motion. For this apparition, Mars will be in retrograde from September 9 through November 14.
Mars will be brilliant throughout October, and will appear even more so because it lies in one of the darkest parts of the sky. At opposition, the two closest 1st-magnitude stars will be Aldebaran (Alpha Tauri) and Fomalhaut (Alpha Piscis Austrini). Each will lie 49° away.