Planetary Motion

Thousands of years ago, people looked at the sky in wonder, fascinated by the motions of a few wandering stars. Nobody understood where these wandering objects--now named Mercury, Venus, Mars, Jupiter, and Saturn--came from, why they moved, or what drove their motions through the sky. Today, people know these objects are planets, but the quest to reach this understanding took thousands of years, and the consequences were profound. Famous scientists Johannes Kepler, Edmund Halley, Isaac Newton, and others discovered the laws of gravity and planetary motion, using these laws to explain the workings of the solar system. Their findings allowed the human race to find its way from planet to planet with unmanned probes and eventually allowed people to reach the moon. In "Planetary Motion," learn how scientists have found new planets outside the solar system, and continue their search for planets like Earth.

Our modern understanding of the heliocentric universe developed five hundred years ago. Since the time of Copernicus and Galileo, scientists have made major strides in understanding how gravity, stars, and planets interact. Gravity, Orbiting Objects, and Planetary Motion explains how early ideas have given way to sophisticated, proven theories about the universe. The book aligns with Next Generation Science Standards and also presents a look at what is next in the cutting-edge field of astronomy.

Examines how the discoveries of Johannes Kepler changed the way scientists viewed the field of astronomy and how the planets moved about the solar system.

To the naked eye, the most evident defining feature of the planets is their motion across the night sky. It was this motion that allowed ancient civilizations to single them out as different from fixed stars. “The Observer’s Guide to Planetary Motion” takes each planet and its moons (if it has them) in turn and describes how the geometry of the Solar System gives rise to its observed motions. Although the motions of the planets may be described as simple elliptical orbits around the Sun, we have to observe them from a particular vantage point: the Earth, which spins daily on its axis and circles around the Sun each year. The motions of the planets as observed relative to this spinning observatory take on more complicated patterns. Periodically, objects become prominent in the night sky for a few weeks or months, while at other times they pass too close to the Sun to be observed. “The Observer’s Guide to Planetary Motion” provides accurate tables of the best time for observing each planet, together with other notable events in their orbits, helping amateur astronomers plan when and what to observe. Uniquely each of the chapters includes extensive explanatory text, relating the events listed to the physical geometry of the Solar System. Along the way, many questions are answered: Why does Mars take over two years between apparitions (the times when it is visible from Earth) in the night sky, while Uranus and Neptune take almost exactly a year? Why do planets appear higher in the night sky when they’re visible in the winter months? Why do Saturn’s rings appear to open and close every 15 years? This book places seemingly disparate astronomical events into an understandable three-dimensional structure, enabling an appreciation that, for example, very good apparitions of Mars come around roughly every 15 years and that those in 2018 and 2035 will be nearly as good as that seen in 2003. Events are listed for the time period 2010-2030 and in the case of rarer events (such as eclipses and apparitions of Mars) even longer time periods are covered. A short closing chapter describes the seasonal appearance of deep sky objects, which follow an annual cycle as a result of Earth’s orbital motion around the Sun.

If the solar system is regarded as a moving mass point system, then both the planet m and the sun M move around the solar system mass center O. According to the motion law of the mass point system and the centripetal force formula of the curve, it can be determined through theoretical analysis and mathematical derivation: (1) Kepler's law of planetary motion contradicts the motion rules of mass point systems. (2) The universal gravitational force F between planet m and sun M. K is the new gravitational constant. The force F' on the object m in the inertial frame S'. In the formula, V' is the velocity of the object m in the inertial frame S', and u is the velocity of the inertial frame S' in the cosmic space reference frame. In addition, the author designed three new optical experiments based on the light interference theory to verify whether the principle of constant speed of light conforms to objective facts. Experiment 1. Using the new front and rear hole laser interferometer for verification; Experiment 2. Verification of using long and short optical path Michelson interferometers; Experiment 3. Verification of using a double-hole interferometer.

This third grade science book discusses the planetary motions of rotating and revolving, and what their effects on Earth are. An understanding of the subject before classroom discussions will yield to more fruitful graded questions and answers. Other pieces of content included in this book will further your child’s knowledge on space science. Grab a copy today.

Reprint of the original, first published in 1881.