Boys trained in the fundamentals of navigation may become technicians in the armed service, Los Angeles, Calif. Thomas Graham, a member of the Victory Corps at Polytechnic High School, is learning to use a sextant to determine longitude and latitude (LOC)
by The Library of Congress

Palmer, Alfred T.,, photographer. Boys trained in the fundamentals of navigation may become technicians in the armed service, Los Angeles, Calif. Thomas Graham, a member of the Victory Corps at Polytechnic High School, is learning to use a sextant to determine longitude and latitude 1942 Sept. 1 transparency : color. Notes: Title from FSA or OWI agency caption. Transfer from U.S. Office of War Information, 1944. Subjects: Los Angeles Polytechnic High School Navigation Scho . . .

Earth Aurora (Auroral X-ray emission observed from Earth's north polar region.)
by Smithsonian Institution

Description: The bright arcs in this Chandra image show low-energy X-rays (0.1 - 10 kilo electron volts) generated during auroral activity. The image - seen here superimposed on a simulated image of Earth - is from an approximately 20-minute scan during which Chandra was pointed at a fixed point in the sky while the Earth's motion carried the auroral region through the field of view. Auroras are produced by solar storms that disturb Earth's magnetic field and accelerate electrons which sp . . .