How the moon was made

How the moon was made

People always wonder how the moon was made. The birth of the planets 4.5 billion years ago was extremely violent. They grew to full size by absorbing rival planet embryos in a series of titanic collisions—one of which probably gave Earth its moon (below). The moon’s large size, low density, and other features suggest that it emerged from an explosion […]

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A deadly fever spreads

A devastating disease caused by airborne fungal spores is colonizing the Southwest in what the Centers for Disease Control and Prevention calls “a silent epidemic.” The disease, coccidioidomycosis, or valley fever, strikes more than 20,000 people per year in the region, 10 times the number it did 15 years ago. The spores live in the soil until wind lifts them […]

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