When I fly up, I see how my Sun's shadow on Earth is getting bigger but dimmer as the Sun's light is reflected from other objects.
As I flew higher and higher in the direction of the Sun, the Earth got smaller, and eventually, I could cast a shadow on the entire Earth. At this point, no reflection will make my shadow dimmer as I will be covering everything.
However, the closer I get to the Sun, the bigger its angular diameter gets, and I am running into another problem where I am not big enough to cover all its light.
What is the minimum size of an object to cast a shadow on the entire Earth? How far away from Earth should it be?
Assume the Earth is at a distance of 1 AU from the Sun at 0.527 degrees.
Bonus question: Would it be realistic to terraform Venus by temporarily freezing it, by blocking the Sun?