How do we know that Earth is a sphere?
What natural indicators can you note that help tell you that Earth is at least round?
Ships sailing into the horizon, Earth’s shadow during a Lunar Eclipse, contrails, time difference around the world and photos from orbiting space crafts
Where might you see the North Star, Polaris, in the sky at these locations: the North Pole, NYC and the Equator?
What do satellites need to transmit data around the world?
LINE OF SIGHT, they can’t chat with one another if the curvature of Earth gets in the way.