What is stellar parallax? Why were ancient peoples unable to detect it?
Explain why the existence of stellar parallax constitutes proof that the Earth really does orbit the Sun.” Stellar parallax is “an apparent shift in the position of a nearby star as we look at it from different places in the Earth’s orbit” (The Cosmic Perspective, 53). Ancient people were unable to detect it because the stars are so far away so it’s difficult to see with the naked eye. Therefore they assumed it wasn’t happening which justified their belief that everything revolved around the Earth. Stellar parallax proves that the Earth orbits the Sun because there isn’t another explanation for being able to get two viewpoints of the same object. 9. “Describe the basic characteristics of the orbit of the Moon. What is the difference between a lunar month and a sidereal month? Why are they different?” The Moon, located an average distance of 380,000 km away, orbits the Earth at an average speed of about 3,680 km/hr and completes its orbit in about 27.25 days. The orbit is tilted about f
