Water in the Universe

Due to its specific chemical and physical properties aater is essential for life on Earth. And it is assumed that this would be the case for extraterrestrial life as well. Therefore it is important to investigate where water can be found in the Universe. There are places that are completely dry, places where the last rainfall happened probably several 100 million years ago but surprisingly this substance is quite omnipresent. In the outer solar system the large satellites of Jupiter and Saturn are covered by a thick layer of ice and perhaps below that there is a liquid ocean.