What feature differentiates Mars from Neptune when comparing observable atmospheric characteristics?

Mars is characterized by a surface blanketed in silicate dust, unlike Neptune's deep, dynamic gaseous layers

The primary observable difference between Mars and Neptune lies in the nature of their major atmospheric/surface features. Mars is defined by its dusty surface, where fine, oxidized material blankets the ground and generates planet-swallowing storms. Neptune, conversely, is known for its gaseous nature, where observable features relate to intense winds and dynamic storms occurring deep within its thick, swirling atmospheric layers, rather than surface particulate blankets. Mars's unique conditions—thin atmosphere, low gravity, and fine oxidized dust—are essential for its dust phenomena, a condition completely absent on the gas giant Neptune.