Washington: Opposition -- the most significant Martian date on stargazers' calendars -- is also when the planet is at its brightest and near its maximum apparent size in telescopes. Because of the shapes and orientations of the planets' orbits, however, Mars and Earth were actually closest on Tuesday, October 6, separated by just 62 million kilometres, said Sky & Telescope.
For Mars, it is more than 160 times farther than the Moon. The planet would not be this near us again until 2035.
Mars oppositions occur at roughly 26-month intervals when Earth catches up to Mars as the planets circle the Sun. This year's opposition is special because it occurs close to when Mars reaches the point in its orbit that is closest to the Sun, called perihelion. The planet's orbit is distinctly out of round (its eccentricity is 0.09 versus 0.00 for a perfect circle), so at times Mars can be up to 21 million kilometres closer or farther from the Sun than average.