NEWTONIAN GRAVITY!




Any object in space, wherever it is or however it is moving, is acted on only and exclusively by gravity.


ORBITING THE EARTH!

An object can orbit the earth in any direction roughly tangent to the earth's surface; the center of the orbit is close to the center of the earth.  Orbits can be anything from nearly circular to very elliptical.



The International Space Station is by far the largest man-made object orbiting the earth. Its period is about 90 minutes, and its orbit is only about 220 miles above sea level.






NEWTON'S CANNON

Why does the crew of the ISS float in midair unless they hold tightly onto something?

Elliptical Orbits!

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