Caption: 
New Southwest Research Institute-led modeling that accounts for material strength found fundamental changes in how the Moon forms after a giant collision between a Mars-sized impactor and Earth. Simulations that neglect strength (top) produce a debris disk that forms the  Moon over time while those factoring in strength (bottom) can produce an intact Moon. These conditions generally correspond with hotter (top) and colder (bottom) colliding planets, which would generally correspond to earlier versus later collision timing. These conditions could also affect the composition of the Moon and the Earth, which remains an open question in the scientific community.