From the “shmeaty” goodness of a test-tube hamburger to the glimmer of water on Mars, it’s been a year in science to remember—and in some cases (yep, we’re talking to you, comet ISON) to forget. Here are some of our picks for the year in science. We’ll share one of our top science stories each day of the first week of 2014. See them all at #2013SciencePicks.
5. Water on Mars
After celebrating its first anniversary on Mars, NASA’s car-sized Curiosity rover sent a gift back to Earth, discovering water in the Martian soil—along with other evidence that the Martian environment was once habitable. http://www.nasa.gov/mission_pages/mars/main/
While water in small amounts appears colorless, most large bodies of water appear blue due to the selective absorption and scattering of white light as well as the blue sky’s reflection. Lakes and oceans get their many hues—ranging from clear blue to muddy brown—in part from suspended sediment and microscopic living matter such as plankton. The 32 swatches in the Color of Water exhibit offer a clue to what elements might affect the color of the San Francisco Bay as it changes day to day or even moment to moment. What color is the bay today?
At the Exploratorium exhibit Icy Bodies, thin shavings of dry ice, warmed by the water they are floating in, emit cold jets of carbon dioxide gas. As the jets of gas shoot out, they spin the dry ice in a spiral pattern. As water vapor in the nearby air condenses into clouds, the pattern is revealed.
Ice balloons tinted with food coloring create a lesson in water phenomena for teachers at the Exploratorium. To see Exploratorium physicist Paul Doherty discuss ice balloons and other chilly phenomena, check out Ice Stories: Dispatches from Polar Scientists.