[填空题]
Halley’s comet orbits thed9x+ns+gatn..; xi. ixzwr9w Sun roughly once ev6fqe- dk+,w8iddo ;iaery 76 years. It comes very close to the surface of the Sun on its closest approach (Fig. 5–39). Estimate the greatest distance of the comet from the Sun. Is it still “in” the Solar System? What planet’s orbit is nearest when it is out there? [Hf iqea8-;d6wi kd+d, oint: The mean distance s in Kepler’s third law is half the sum of the nearest and farthest distance from the Sun.] $\times 10^6$
