Nightime in the americas model of the sun, moon, and earth

the entire statement is true and correct.  

there's no diagram, nothing is illustrated, and no question is asked.

the only real purpose of sputnik 1 was to beat the us into space. we were getting close to launching a useful satellite, explorer 1 - which launched on january 31, 1958. the ussr had to beat that, so they launched sputnik 1 on october 4, 19