Mars is passing the magnificent star called Antares, “anti-Mars.” The middle of Sep. 28 by Universal Time is when they are closest together, so they are nearly at their closest on the evenings of Sep. 27 and 28.
The conjunction of Mars with this or any star happens at intervals of about 23 months, Mars’s cycle around the Sun. The way it looks from Earth varies according to Earth’s own position at the time. Last time, on 2012 Oct. 20, Mars passed 3.6 degrees north of Antares, and they appeared 42 degrees east (left) of the Sun. This time, they are 65 degrees from the Sun, therefore more conveniently high in a darker post-sunset sky; and Mars is passing slightly closer north of the star, 3.1 degrees. But that is still a wide gap (about 1,900 times the width of Mars’s tiny 6-second disk). Mars is moving east at less than 3/4 of a degree a day.
Planet and star appear equal in brightness; Mars is brighter by an amount imperceptible to the naked eye (their magnitudes are 0.8 and 1.0). This is despite an enormous difference of distance! Mars at this time is 1.52 Sun-Earth distances from us (the Sun-Earth distance, or astronomical unit, is 93 million miles). Antares is at 600 light-years – about 25 million times farther.
Antares is the southernmost of the four great stars that lie close to the path of the Sun, Moon, and planets (the others being Aldebaran, Regulus, and Spica). It lurks ruddily in the lower sky; I love the many other names for it that you can extract, a little shakily, from R.H. Allen’s fine old book on star names – the Heart of the Scorpion, of course, and Tyrannus, the Rebel, the Bat Star, Vespertilio, the Rustle of Evening.
There is a box in Astronomical Calendar 2014 about Antar, the black “Arabian Hercules,” pre-Islamic hero-poet to whom some, entertainingly though presumably falsely, attribute the name of the star.
When I came upstairs from writing this to breakfast, the radio was playing over and over the ominous gallop of “Mars, the Bringer of War”: someone was giving an analytical review of many orchestras’ recordings of Holst’s “The Planets.”