When the Galileo spacecraft reached Jupiter on December 7, 1995, Jupiter was almost at conjunction with the Sun. Given that it takes 8 1/3 minutes for light to travel a distance of 1 au, how long did it take Galileo's signals to reach Earth from Jupiter? (A diagram might help to envision this configuration.)

Question

Quizplus · Accepted Answer

At conjunction, Jupiter is approximately 5.2 astronomical units (au) from Earth. Since light takes 8 1/3 minutes to travel 1 au, the time taken for signals to travel from Jupiter to Earth is 5.2 au * 8.33 minutes/au = approximately 43 minutes.

When the Galileo Spacecraft Reached Jupiter on December 7, 1995