Kepler's 1st law states that the orbits of the planets around the sun and makes an ellipse. This is taught in astronomy.
It is Kepler's first law which says the planet moves in an ellipse with the Sun occupying one focus and the other focus is vacant.
It is a theory that states the planets revolve around the sun in our solar system.
"The Law of Orbits: All planets move in elliptical orbits, with the sun at one focus." Source: Hyperphysics This means that at some points during its elliptical orbit, the Earth is closer to the Sun than at other times. (For example, semiminor vs semimajor points).
Velocity is a indication of speed and direction, so the fact they travel around it means that the direction is continually changing and, therefore velocity is continually changing. Kepler was the astronomer who discovered the laws of motion for the planets. Newton, a century later, derived the laws from his laws of gravity and motion. The first law of planetary motion states that planets orbit the sun in an elipse. So the speed is continually changing.
The Heliocentric Theory is the theory that states the Sun is the center of the Solar System and all other celestial objects revolve around it. Supporting observations about the theory were by Galileo Galilei.
Elliptical orbits of the planets around the sun actually match what we observe. Newton's Theory of Universal Gravitation states that planets will move around the sun in elliptical orbits.
This is known as Keplers 2nd Law of Planetary Motion. It states that line drawn between a planet and the sun sweeps out equal areas during equal time intervals.
It is Kepler's first law which says the planet moves in an ellipse with the Sun occupying one focus and the other focus is vacant.
No, the moon orbits the Earth and the Earth Orbits the Sun. The Earth does not orbit in circular patterns. This is proved by Johannes Kepler. Kepler states that the planets orbit in elliptical.
The closer the planet is to the Sun, the faster it moves.
Bohr's model
It is a theory that states the planets revolve around the sun in our solar system.
The Bohr Model.
"This definition, which applies only to the Solar System, states that a planet is a body that orbits the Sun, is massive enough for its own gravity to make it round, and has "cleared its neighbourhood" of smaller objects around its orbit. Under this new definition, Pluto and the other trans-Neptunian objects do not qualify as planets."
No, the geocentric theory states the Sun orbits the Earth. It has since been shown to be incorrect, thanks to modern astronomical observations and mathmatics.
Planets naturally move in our sky over time and therefore are over different states.
"The Law of Orbits: All planets move in elliptical orbits, with the sun at one focus." Source: Hyperphysics This means that at some points during its elliptical orbit, the Earth is closer to the Sun than at other times. (For example, semiminor vs semimajor points).