Mars at Closest Approach to Earth Since 2005, and the Mayans Saw It Coming

Mars is closest to Earth on Memorial Day, May 30, for the year, a distance not seen since before 2005; the next close approach isn't till 2018.

You might have seen a ruddy, unblinking light in the night sky lately, more or less in the vicinity of the moon. That is Mars zooming in for its closeup, and on Monday May 30 Mother Earth’s neighbor, the fourth planet from the sun, will be the closest it has been to us in more than a decade.

“Mars is out almost all night long now. It looks like a bright reddish star, shining with a steadier light than the twinkling stars,” says Earthsky.org. “Look for Mars in the eastern sky at nightfall—highest in the sky near midnight—and in the west as morning dawn starts to light the sky.”

Mars is especially visible this month because it reached both opposition—meaning it was exactly opposite the sun in the sky as viewed from Earth—and its closest approach to our planet, which is just under 50 million miles away. While Mars normally makes it closest approach to Earth every 26 months, this year’s proximity is special. Astronomy.com has even gone so far as to nickname this the Summer of Mars.

“This Monday evening (May 30) at 5:35 p.m. EDT (2135 GMT), Mars will be the closest it has been to Earth since October 5, 2005,” says Space.com. That is, it will be 46.7 million miles away, which at half the distance between the Earth and the sun, constitutes half an astronomical unit (AU). An AU is based on Mother Earth’s average distance from our star, which is about 93 million miles (150 million kilometers).

“After 5:35 p.m. EDT on that date, Mars will begin to recede from Earth,” says Space.com.

The reason for all the excitement: it makes Mars much easier to see, both with the naked eye and with a telescope.

“It is now shining nearly on par with the planet Jupiter, and it’s not very often that Mars can match Jupiter in brilliance!” says Earthsky.org.

Overall, Mars is brightest this month and early into June, starting on May 18 and going through June 3, according to NASA, which advises, “Simply go outside and look up, contact your local planetarium, or look for a star party near you.”

Graphic: NASA/JPL-Caltech

In 2016, Mars will appear brightest from May 18-June 3. Its closest approach to Earth is May 30. That is the point in Mars’ orbit when it comes closest to Earth. Mars will be at a distance of 46.8 million miles 75.3 million kilometers).

Mars has been an object of human attention since time immemorial. The ancient Maya mapped the red planet’s orbit, according to a study published in the journal Proceedings of the National Academy of Sciences in 2001. They did it in such a way that “permitted the tracking of Mars across the zodiac and the relating of its movements to the terrestrial seasons and to the 260-day sacred calendar,” researchers at Tulane and Colgate universities found.

The researchers even compared the Mayans' insights with those of the 16th-century astronomer and mathematician Johannes Kepler, who created a way to predict planetary motion.

“While Kepler solved the sidereal problem of Mars by proposing an elliptical heliocentric orbit," they said, "anonymous but equally ingenious Maya astronomers discovered a pair of time cycles that not only accurately described the planet's motion, but also related it to other cosmic and terrestrial concerns.”