Mars is putting on quite a show for skywatchers this month.
For most of October, Mars will be brighter in the night sky than anything else in its vicinity, offering people a clear view of the red planet. Mars is also days away from reaching “opposition,” a celestial alignment in which Earth, Mars and the sun form a straight line in space, with Earth in the middle.
Mars will be at opposition Oct. 13. On that day, Mars will rise as the sun sets, reach its peak in the night sky at midnight, and then set as the sun rises again. If it’s a clear night, skywatchers can expect the red planet to outshine anything else in its region of the sky.
Mars oppositions typically occur every 26 months. Since Earth is closer to the sun, it circles the star two times in roughly the time it takes Mars to complete one orbit. Oppositions can occur at any point in Mars’ orbit, according to NASA, but occasionally the alignments happen around the time when Mars is closest to the sun, as is the case this year.
Mars reached the point in its orbit when it was closest to the sun — an orbital event known as perihelion — on Aug. 3. When it aligns with the sun and Earth several weeks later, it’s known as “perihelic oppositions.” These events are considered rare because they only occur once every 15 or 17 years, according to NASA.
The best way to see Mars is to head outside in the early evening and gaze just above the horizon in the eastern sky. If conditions are clear, Mars will be the brightest object in that region of the sky, appearing as a distinct, reddish-orange “star.”
Mars will be visible to the naked eye for most of October, but amateur astronomers with telescopes may also be able to glimpse features on the planet’s surface.
Mars made its closest approach to Earth on Oct. 6, when the two planets were separated by just 38.6 million miles, according to NASA. It will not pass this close to Earth again until 2035.
For skywatchers in the Northern Hemisphere, this year’s opposition is expected to be particularly impressive because of Mars’ position in the sky.
“Indeed, Mars won’t be comparably close and well-positioned for northern observers again until it reaches opposition in 2052, making this year’s opposition all the more noteworthy,” Gary Seronik, consulting editor for Sky & Telescope magazine, said in a statement.