Tycho Brahe's model of the solar system had the earth motionless and fixed at the center with the sun and stars moving around the earth, but he incorporated Copernicus' heliocentric model so that the other, non-Earth planets orbited around the sun. Brahe admired Copernicus' work and how it could explain the observed motion of planets, but he did not agree that the earth moved.Know More
In 2 AD, Ptolemy developed a model of the solar system that had the earth at the center and the sun, planets and stars moving around the earth. Most observations seemed to validate this model, except for observations of the planets. Mars, in particular, could be observed to "wander," moving backward and then forward again at various points. Ptolemy and others tried to address the issue with epicycles, positing that Mars was in orbit around the earth but also in another smaller orbit around itself. The epicycles didn't work well mathematically, ultimately leading to Copernicus and his model with the sun at the center and the earth in orbit around it.
Tycho Brahe, who had developed very accurate instruments to measure planetary motion, did not believe the earth could also be in motion. His data suggested that the sun and stars orbited the earth, but like many others he found Ptolemy's epicycles problematic. By incorporating Copernicus' model of the planets orbiting the sun he felt he had addressed the mathematical issues surrounding epicycles while preserving the widely held belief that the earth was at the center of the solar system, and that all the heavenly bodies revolved around it.Learn more about Planets
The largest object in the solar system is the sun. The sun has a mass of 1.989 x 10^30 kilograms, which is 99 percent of all the mass in the solar system.Full Answer >
Simply put, planets in the solar system revolve around the sun and the solar system is held together by its own gravitational field. The solar system consists of nine planets, the sun, each planet's moons, comets, asteroids and meteors.Full Answer >
Mars occupies the fourth closest position to the sun in the solar system. Earth, along with Venus and Mercury, are all closer. Mars is bordered by both Earth and Jupiter.Full Answer >
To make a model of the solar system, hang circles representing the planets from a larger circle of cardboard. By varying the length of the string and hanging the cardboard planets in orbital circles, the model is even more precise.Full Answer >