At 11 p.m., the only sounds at Triton College in River Grove are the hum of parking lot lights, the trucks on 5th Avenue and, lately, quiet speculation about coming dust storms on Mars.
Dan Troiani is on the steps of the college’s Cernan Space Center with a telescope aimed beyond the lights of Maywood Park.
In the sky above, and in amateurs’ eyepieces all over the world, Mars is growing ever brighter as its orbit carries the Red Planet closer to Earth than it’s been in more than 59,600 years.
There is virtually no practical benefit to Mars’ close approach this year beyond helping NASA predict Martian weather–an important enough service with hundreds of millions of dollars invested in Mars landers.
But it is a splendor, a brightening feature in the night sky, that has attracted the attention of casual observers and delighted others with its deepening flame-orange hue.
At 4:51 a.m. CST on Aug. 27, the planet will be a mere 34.6 million miles away–a distance measurable in light-seconds. It takes eight minutes for light to travel from the sun to Earth.
Though Mars and Earth are on the same side of the sun every two years, they make close passes to each other only every 15 to 17 years–when Earth’s orbit is farthest from the Sun at the same time that Mars’ orbit is nearest the sun.
The last time such a close pass occurred was 1988, when the planets were some 1.5 million miles farther apart than they will be this year.
Extremely close passes–like the one this year, another that occurred in 57,617 B.C., and future passes in 2287 and 2729–happen irregularly and more infrequently because of changing shapes and tilts in the planets’ orbits, said Mark Hammergren, an astronomer at Adler Planetarium.
“It just happened that they conspired to give us a particularly close approach this time,” he said.
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Compiled from RedEye news services and edited by Patrick Olsen (polsen@tribune.com) and Drew Sottardi (dsottardi@tribune.com)
