The International Space Station orbits at an altitude of about 250 miles about Earth’s surface. The radius of Earth is approximately 3963 miles. How far can an astronaut in the space station see to the horizon? Round to the nearest mile.

In this case we are dealing with the pythagorean theorm involving right angled triangles. This theorm states that a^2 + b^2 = c^2 which means the square of the hypotenuse (side c, opposite the right angle) is equal to the square of the remaining two sides.

In this case we will say that a = 3963 miles which is the radius of the earth. c is equal to the radius of the earth plus the additional altitude of the space station which is 250 miles; therefore, c = 4213 miles. We must now solve for the value b which is equal to how far an astronaut can see to the horizon.

(3963)^2 + b^2 = (4213)^2
b^2 = 2,044,000
b = 1430 miles.

The astronaut can see 1430 miles to the horizon.