At 2 o’clock on a recent morning, Bob Bunge ambled into the inky darkness of his Bowie back yard and prepared to meet an old friend. He swung the end of a massive home-built telescope skyward, gazed over the branches of a silver maple tree, then zeroed in on Earth’s nearest neighbor. “Mars is as bright as I’ve seen it in my 23 years of amateur astronomy,” he said, marveling at the detail he could spot on the Red Planet: the shimmering southern polar ice cap, and the alternating bands of darkness and lightness that gave Mars the mottled look of an overripe orange.