Europa is a puzzle. The sixth largest moon in our solar system, Europa confounds and intrigues scientists. Europa has a mean distance from Jupiter of 670,900KM and orbits the gas giant in just three and a half days. Few bodies in the solar system have attracted as much scientific attention as this moon of Jupiter because of its possible subsurface ocean of water. We cannot resist the mystery of Europa and its potential for possessing an ocean.

In 1979, the two Voyager spacecraft flew by Jupiter and its moons, giving us our first close-up view of Europa. In 1995, the Galileo spacecraft began gathering more detailed images and measurements within the system. Making sense of this chaotic landscape is a challenge to planetary scientists.

Many planetary scientists are now trying to plan the perfect mission to visit Europa. They are trying to model its traits based on the little bit of information we have from the previous fly-by missions. We know that the frozen crust on top of the ocean has ice and probably has something else (a kind of salt). In order to visit Europa and sample the ocean, we need to know how thick this crust is.

“Scientists make models to estimate the crustal thickness, but they assume that this crust is composed of just ice,” states Christine McCarthy, student/research assistant at Brown University. “We’ve discovered through our experiments that, for certain kinds of salt (we’re trying all the salts that are suggested by the spectra), the combination of ice and salt is a lot stronger than just the ice alone. That should change everyone’s estimations of how thick the crust would be.”

Christine chose KaleidaGraph to plot and analyze her important research. “I use Double-Y scatter plots to show the true strain and the stress plotted against time for my creep experiments. I mask out a nice linear region of the strain plot and curve fit to obtain the steady-state strain rate. Finally, I plot the stress and strain rate points on a log-log plot.”