a) Describe how we measure distance using parallax. What is the practical limitation of this technique, and what is the approximate distance (in parsecs) out to which this technique is useful.
b) Procyon, or α-Canis Minor, is 11.46 light years from the Sun. Suppose that you were on a space ship that flies from Earth directly away from the Sun and out to the orbit of Jupiter, 5.203 AU from the Sun. How much would the angular position of Procyon change relative to far more distant stars during your voyage?