Water Lust: Why All the Excitement When H20 is Found in Space?

The article is about the importance of water and its properties. The article addresses why water is so important to life and why finding water in any of its forms on other planets could signal that there is life there as well.

Water in various states has been found in the craters of mars, the moon, the poles of Mercury, the clouds of Venus, on Mars, inside asteroids and comets, and on Jupiter, Saturn, Uranus and Neptune. It has also been found on several of Jupiter's moons and inn the atmosphere of stars.

Water is so important because life on Earth requires it. Sushil Atreya from University of Michigan Ann Arbor's Planetary Science Laboratory says "liquid water acts as a solvent, as a medium and as a catalyst for certain types of proteins, and those are three main things that allow life to flourish."

Liquid water's property as a solvent, comes from its molecular structure. The oxygen atoms hold their electrons more strongly than the hydrogen atoms do, so they accumulate a negative electrical charge, while water's hydrogen atoms are positively charged. Also, more things dissolve in it than in other kinds of solvents. Water is "an ideal medium in which chemical reactions can occur and nutrients can be easily transported." Furthermore, water can remain a liquid in very high or very low temperatures.

One very important property is that ice floats. Frozen water is less dense than its liquid form, this allows water to be present under the ice instead of entire bodies of water being frozen solid. This makes life possible in places like Europa, (Jupiter's ice-covered moon. Scientists suspect it to have a liquid water ocean under the ice. Finally, water absorbs infrared radiation, so it can store heat and maintain temperatures.

This article is an example of discovery science because it gives enough information to propose that life can be found on other planets, but no experiments were conducted. This research is important for humans because it is one step closer to discovering life on other planets.

Online Article

by: Bruce Lieberman

October 4, 2009

Scientific American