How can such small targets be accurately hit so far away?
I would like to know how astronautical engineers and spaceflight planners are able to measure points in space that are so far from us, such as the edge of a planet or the moon, with the accuracy needed to calculate and aim the path of a rocket or probe. It seems that there is no device that could measure the exact coordinates of the far off object, then measure precisely that object’s edge, determine from them the precise time and angle of the flight path for orbital deceleration, and then steer a rocket exactly to its target! Reply I am neither astronautical engineer nor spaceflight planner, so my answer must be hedged with “that is what I believe.” We can determine positions of celestial objects fairly accurately by telescope, A fix within of one second of arc (1″) means an error of 0.78 km at a distance of a million kilometers–nearly 3 times the distance of the Moon. But actual accuracy is even better. We have sent space probes to (say ) Jupiter, and from the delay of radio signals
