The Atlantis Massif is an oceanic core complex at 30°N on the Mid-Atlantic Ridge on the north side of the Atlantis I transform fault, which offsets the ridge by ~60 kilometers. The massif is capped by a corrugated fault zone, and is composed of a large gabbro intrusion into serpentinized mantle rocks to the south. These altered mantle rocks host the Lost City hydrothermal field, which is famous for carbonate chimneys the height of a house, venting alkaline fluids rich in hydrogen and methane. The hydrogen is formed by the reaction between seawater and mantle mineral oliv- ine, and is a powerful source of energy that may have fueled the formation of the first building blocks of life on Earth. Before life could begin, small organic molecules must have formed abiotically. Scientists have suggested that vent fields such as Lost City may be an analog of systems where these prebiotic reactions occurred, leading to the early development of life. Similar systems may be present on “icy worlds” such as Enceladus, which is one of the moons of Saturn, and capa- ble of supporting life.