Most stone is made over millions of years, cooked in the core of our planet. That stone then erodes over time due to wind, acids found in rain and groundwater, and other natural weatherings. Chalk is a type of limestone formed by the shells of microscopic marine organisms. The process of erosion can produce beautiful
Read moreMeet New Horizons: 7 Space Experiments
January 19, 2006. A piano-sized robot blasts upwards from Earth on a massive rocket and escapes the gravity of our home planet, bound for distant adventures. For a small community of scientists, launch day kicks off the long closing chapter of a story years in the making. To most of the world, it’s the beginning
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