Which planet is Mars’s inner neighbor in the order from the Sun? Earth is Mars’s inner neighbor.
The planets outward from the Sun are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Earth therefore lies immediately inside Mars’s orbit, making it Mars’s neighboring planet toward the Sun. Earth is about 1 astronomical unit from the Sun on average, while Mars averages about 1.52 astronomical units.
Mars and Earth are both terrestrial, or rocky, planets. Their neighboring orbits make Mars an especially important target for exploration, even though their distances from each other change substantially as both planets travel around the Sun. At their closest, they can be roughly 54.6 million kilometres apart; at other times, they are far farther away.
Venus is a frequent mix-up because it is also an inner planet, but Venus is two orbital positions inward from Mars, with Earth between them. Mercury is closer to the Sun still, while Jupiter is Mars’s outer neighbor.