At 10 a.m. eastern time tomorrow, Mars will be 38.57 million miles away from Earth, the closest it will be in the current Martian year. Both planets will continue orbiting the sun, so the moment will be fleeting, but it will be bookended by some quality planet-gazing opportunities.
As Mars is the fourth-brightest celestial body, after the Sun, moon, and Venus, you don’t need a telescope to spot it in the southern sky, where it will reach its highest point around midnight. And because it’s so close, Mars will be particularly large and easy to spot sans telescope.
Mars always hits its closest approach to Earth near its opposition, the point at which it is positioned directly on the opposite side of the Earth from the Sun. Because neither planet has a perfectly circular orbit, they never line up perfectly.
The amount of time between these moments can be as long as eight-and-a-half days, as it was in 1969, or as little as ten minutes, as it will be in 2208 and 2232. This year, the opposition and closest approach moments fall a week apart, as Mars will reach opposition on October 13.
Because the Martian year is 687 days long, or nearly two years on Earth, opposition happens roughly every other year, so it will be a while before you and your kids have this kind of opportunity again.
The closest approach in recent memory was in 2003 when Mars was just 34.65 million miles away. It won’t come as close as it will be this month until September 2035, so you should definitely make an effort to check it out tonight or tomorrow night, or else you’ll have to wait another 15 years.