Kepler orbit led to Johannes Kepler working on his celestial mechanics. He later became known as the father of calculus. In 1601, Johannes Kepler acquired the extensive, meticulous observations of the planets made by Tycho Brahe. Kepler would spend the next five years trying to fit the observations of the planet Mars to various curves. In 1609, Kepler published the first two of his three laws of planetary motion. The first law states: More generally, the path of an object undergoing Keplerian motion may also follow a parabola or a hyperbola, which, along with ellipses, belong to a group of curves known
History of Solar System formation and evolution hypotheses once a star has exhausted all its nuclear fuel can it collapse to such a small size, and so planetary nebulae came to be understood as a final stage of stellar evolution. Spectroscopic observations show that all planetary nebulae are expanding, and so the idea arose that planetary nebulae were caused by a star's outer layers being thrown into space at the end of its life. Over the centuries, many scientific hypotheses have been advanced concerning the origin of Earth's Moon. One of the earliest was the so-called "binary accretion model", which concluded that the Moon accreted from material in