The distance between Earth and Mars varies between 40 and 225 million miles. Since planets orbit the sun in an elliptical path rather than a circular path, the distance between the two planets changes throughout the year.
Every 26 months, Mars and Earth reach their closest point to one another. According to NASA, this is referred to as opposition of Mars because Mars and the sun are on the opposite side of Earth. When an opposition of Mars occurs, this nearby planet is easily visible in the night's sky along with its red tint, which is why it was nicknamed The Red Planet.