He thought that they were moons
but it was actually the rings of the planet
The oceans cover 71 percent of the Earth's surface and contain 97 percent of the Earth's water. Less than 1 percent of the Earth's water is fresh water, and 2-3 percent is contained in glaciers and ice caps. The oceans contain 99 percent of the living space on the planet.
It can help Bacteria reproduce quickly since it requires one organism and when needed to repopulate it doesn't take long.