Space advocates have long speculated that lava tubes on the Moon or Mars would provide an ideal protective enclosure for space settlements. The benefits include protection from radiation, micrometeorite bombardment, temperature extremes…the list goes on. Now, in a study published in Earth-Science Reviews, researchers at the the Universities of Bologna and Padua have found that lava tubes on these worlds could be 100 to 1000 times larger then on Earth, because of their lower gravity and the resultant effect on volcanism. Such roomy and stable subsurface chambers would be ideal for spacious space settlements.