Mercury Stays Closest to Earth 47% of the Time, Beating Venus on Average

2 articles · Updated · spacedaily.com · Jun 3

A 10,000-year orbital simulation found Mercury was Earth’s nearest planet about 47% of the time, versus 36% for Venus and 17% for Mars.
That result comes from averaging distances across all orbital positions, rather than using the common shortcut of subtracting planets’ average distances from the Sun.
Venus still makes the closest single approach to Earth—about 38 million kilometers—and its orbit remains the one nearest Earth’s, so the usual answer depends on how “closest” is defined.
The same calculation suggests Mercury is the average nearest planet to every other planet because its tight orbit around the Sun keeps it from spending long stretches far away.
For missions, the finding changes a piece of planetary trivia, not flight planning: launch geometry and close-approach windows still make Venus and Mars the practical near targets.