This webpage from National Aeronautics and Space Administration (NASA) provides an astronaut’s photograph of the moon viewed from the top of the atmosphere. The appearance of the nearly translucent moon is described in...

This National Aeronautics and Space Administration site describes long-term changes in Earth's magnetic field, and how magnetic stripes in the Atlantic seafloor provide evidence for reversals of this field. The site...

Earth's Magnetic Personality is the fourth and final teacher's guide in a sequence of four guides designed to understand magnetometer data and the THEMIS mission science while meeting the needs of high school teachers...

These web pages, authored by Nick Strobel, contain material explaining Einstein's general and special theories of relativity. Gravity and warped spacetime are included, along with explanations of the impact on...

A collection of some 25,000 historical photographs, slides, lithographs, engravings, and other visual materials, focusing on American physicists and astronomers of the twentieth century, but including many scientists in...