Our planetary neighbors are making a visit later this month. On August 27, Mars will be less than 34.65 million miles away. This close encounter is extremely rare. The last time it was that close was September 12, 57,617 BC when it was 34.62 million miles, and the next time it will make a close pass will be in 2287.
Earth and Mars line up with each other quite regularly – about once every 26 months, but neither orbit is perfectly circular. Earth’s orbit varies it’s distance to the sun by about 2 percent, while Mars varies by 9 percent. The trick is to match the furthest point of the Earth orbit with the closest part of the Martian orbit matched with this 26 month cycle.
As we near August 27, Mars will be the brightest object in the southern sky (except the sun and moon), although it will not look any bigger than it normally does.