Video Description:  The Moon impacts Earth through tides and moonlight. NASA missions to the Moon continue to help us discover more about our nearest neighbor. Learn more about Moon mapping and resources. Video Length:  2:49. NASA eClipsTM is a suite of online student-centered, standards-based resources that support instruction by increasing STEM literacy in formal and nonformal settings.  These free digital and downloadable resources inform and engage students through NASA-inspired, real-world connections.NASA eClips Our World videos (grades 3-5) help students understand the differences between science (the natural world) and engineering (the designed world).  These video segments supplement elementary learning objectives not only in science, technology, engineering and mathematics, but also in reading, writing, visual and performing arts. 

In this activity, students learn about ocean currents and the difference between salt and fresh water. They use colored ice cubes to see how cold and warm water mix and how this mixing causes currents. Also, students learn how surface currents occur due to wind streams. Lastly, they learn how fresh water floats on top of salt water, the difference between water in the ocean and fresh water throughout the planet, and how engineers are involved in the design of ocean water systems for human use.