lowgravity

Low gravity refers to environments where gravitational acceleration is significantly less than Earth’s 9.81 m/s^2. It occurs on the Moon (about 1.62 m/s^2, ~0.165 g), Mars (about 3.71 m/s^2, ~0.38 g), and smaller bodies such as asteroids. Microgravity, by contrast, describes near-weightlessness experienced in orbital free fall. These conditions affect movement, structure, and biological processes differently from both Earth gravity and ordinary low gravity.

In reduced gravity, weight-bearing loads are smaller, altering locomotion and the mechanical stress on bones and muscles. Prolonged exposure can lead to bone mineral density loss, muscle atrophy, and changes in balance and coordination. Fluid distribution shifts toward the head, which can affect vision and intracranial pressure. Effects depend on gravity level and duration; Moon gravity produces different challenges than Mars gravity or microgravity.

For surface missions, low gravity influences vehicle and suit design, habitat anchoring, and tool use. Mobility may include hopping or careful stepping, with tethers and foot restraints common. Dust and regolith can pose hazards to equipment and visibility, and low gravity changes the dynamics of landing, sample collection, and construction.

Research uses Earth-based analogs such as parabolic flights and neutral buoyancy facilities, alongside lunar and Martian analog environments. These studies help plan health countermeasures, mission architecture, and operations for future exploration of low-gravity bodies.