The sun. But at the center of our galaxy (Milky Way) is a supermassive black hole called Sagittarius A- star
Let's say that the land has pollution meaning there is trash everywhere and dead plants over there, with those types of pollution it will harm our water supply because sometimes the pollution can affect our water.
Clearing the lands that has pollution can do good for our water and our ecosystem. When we clean the lands, more plants are able to grow, animals build their homes there, etc. That means that the animals and/or plants have a drinking water that is safe to drink and isn't polluted because we cleaned the land and the water.
Keep America clean.
Hope this helped :)
Have a great day
The sequence of events that can lead to magma becoming soil is C. crystallization followed by exposure and weathering. Under these circumstances it may happen that magma actually turns to soil - it cools off so much that it becomes the ground we walk upon.
If your question is literally how long they could remain without water, the answer is 1-2 days with major side effects, and 3-4 with certain death.