Water, water, everywhere!

When it comes to space exploration, nothing makes the news quite like the possibility of finding extra-terrestrial water. Just over a month ago,  a research team from Japan used the Subaru Telescope to observe the water-rich atmosphere of Gliese 1214 b, a planet 40 light years from Earth.

Why are we always searching for water in space? What does discovering water have to do with the possibility of discovering extra-terrestrial life? 

To begin answering these questions, we explored some of water's interesting properties through the following investigations:

Water's molecular structure: We made models of water molecules, noting how oxygen and the 2 hydrogens share electrons.

Water sticks to other water molecules and other stuff too: We observed the U-shaped water line in a graduated cylinder and the dome shaped water line, as you fill a cup just beyond the brim.

Water is strangely denser than its solid form, ice. 

Water's a great solvent: We saw how water dissolves marker ink and carries along its components through filter paper.

Finally we discussed why these properties are so important for life as we know it.

General Science: Solutions

This week we learned about solutions, that is liquid mixtures. In particular we wanted to know whether water temperature affects how well something dissolves. First the kids compared the time it takes to dissolve a couple drops of food coloring in different water temperatures. Then they tried to see how much sugar they could stir into solution, once again comparing different water temperatures. They concluded that hot water is much more effective at dissolving solutes (that's fancy-talk for stuff).

We also noted that the final volume of the sugar solution was surprisingly LESS than the sum of the initial water volume plus the sugar. Part of what happens when you dissolve something is that it breaks up into tinier pieces and more spaces open up within the molecules themselves.

Biology: "Newly discovered planet may have water on its surface" ....so what?

Just about a year ago a team of astronomers announced the discovery of an extrasolar planet, called Gliese 581g*. What's neat about Gliese 581g is that it may have liquid water on its surface.  When scientists search for water in space, they're looking for just one thing: life.

What makes water so special, and why do we think it's essential for life? These were some of the questions we set out to explore on day 1 of Biology. We started off by observing water's amazing ability to dissolve other substances. The kids prepared strips of filter paper, each one with a different marker color. After placing them in a bowl of water, we watched as the water traveled up the papers and dissolved the inks, revealing surprising bands of different colors.

We talked a bit about the chemical structure of water and how this structure allows water to dissolve substances easily and in doing so helps along the important chemical reactions necessary to sustain life.

*http://en.wikipedia.org/wiki/Gliese_Catalogue_of_Nearby_Stars

General Science and Biology: Solutions

This week we learned about solutions, that is liquid mixtures. In particular we wanted to know whether water temperature affects how well something dissolves. First the kids compared the time it takes to dissolve a couple drops of food coloring in different water temperatures. Then they tried to see how much sugar they could stir into solution, once again comparing different water temperatures. They concluded that hot water is much more effective at dissolving solutes (that's fancy-talk for stuff).

In the biology group we also noted that the final volume of the sugar solution was surprisingly LESS than the sum of the initial water volume plus the sugar. Part of what happens when you dissolve something is that it reacts chemically with the solvent (fancy-talk for liquid) and/or fits into the spaces within the molecules themselves.