Question

a) What is the greatest possible geocentric latitude of Venus, i.e., how far from the Sun can the planet be at the inferior conjunction? Assume the orbits are circular. b) When is the situation possible? The longitude of the ascending node of Venus is 77◦ .

Answer 1

Venus orbits the Sun at an average distance of about 0.72 AU (108 million km; 67 million mi), and completes an orbit every 224.7 days. Although all planetary orbits are elliptical, Venus's orbit is the closest to circular, with an eccentricity of less than 0.01.When Venus lies between Earth and the Sun in inferior conjunction, it makes the closest approach to Earth of any planet at an average distance of 41 million km (25 million mi). However, it spends a large amount of its time away from Earth, meaning that it is the closest planet to Earth for only a minority of the time. This means that Mercury is actually the planet that is closest to Earth a plurality of the time.The planet reaches inferior conjunction every 584 days, on average.Because of the decreasing eccentricity of Earth's orbit, the minimum distances will become greater over tens of thousands of years. From the year 1 to 5383, there are 526 approaches less than 40 million km; then there are none for about 60,158 years