Sarita's+Page

=Gabriela's page is under mine. so just keep scrolling down.= =Kepler's 3rd Law = 

__General Stuff __
 Johannes Kepler was a German mathematician and astronomer. He earned a Master's degree in philosophy at the University of Tubingen. While he was there, Kepler studied mathematics and theology. His family was poor, so it helped that he had gotten a scholarship to attend that university. Kepler got into teaching and then later, became an assistant to Tychoe Brahe, a Danish astronomer. Kepler learned quite a bit from Brahe and was able to observe all of Brahe's observations in mathematical terms.

Kepler had three laws of planetary motion. His third law of planetary motion states that "The square of the orbital period of a planet is directly proportional to the cube of the semi-major axis of its orbit". That means that the ratio for these two things is the same for all planets. Surprisingly, Isaac Newton was the one who understood why his laws were correct. Kepler on the other hand did not.

Kepler's third law is also called the harmonic law.

It is a mathematical formula that allows us to measure the masses of astronomical objects by examining the relationship of the distance between the planet and the sun and the time it takes to orbit the sun.

To find the mass of any astronomical object, astronomers simply apply Kepler's third law to orbits, which is the only way of figuring out the mass. They are able to figure out a planet's mass by studying the orbits of its moon. If moons had something orbiting them, they would be able to use that to find the mass of a moon, but they don't. So, astronomers have to send probes to be affected by their gravity if they want to find the mass of a moon. By studying the orbits of stars in binary systems, astronomers can find the masses of stars. If a star is not in a binary system, they cannot figure out its mass.





K = the constant of the square of the orbital period of a planet proportional to the cube of the semi-major axis of its orbit.

Planets farther away from the sun have longer orbital periods than those that are closer.

P2 = a3

p= time it takes the planet to orbit the sun a= semi-major axis of the planet's orbit in astronomical units (au)

The semi-major axis is basically just the radius of the ellipse.

An ellipse looks like an oval.

 Aristotle said that the orbits of planets were circles, but Kepler proved him wrong, by realizing that they were in fact ellipses, not circles. This was Kepler's first law.

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Sarita's bibliography "Kepler's Laws of Planetary Motion." __Kids.Net.Au__. 20 May 2009 .

"TheSpaceSite.com :: Johannes Kepler and his Planetary Laws of Motion." __TheSpaceSite.com :: TSS Blog__. 20 May 2009 .

The rest are found on my bibliography page.

Who discovered how to do this?  One of the early scientists to think about the time problem was Galileu Galilei h   e suggested that the pendulum could be used as a clock. He also noticed, using the newly invented telescope, that the moons of Jupiter had a fast speed and could be used as clocks in the sky. But observing the Jovian moons with the telescope proved to be difficult, even on land.  How are each factor (distance and mass) measured? Measuring angular distances is different from measuring altitudes. Instead of the vertical plane, the sextant must be held inclined, so that the instrument plane includes de Earth's center and the two celestial objects.   There is also a navigator lunar calculator   First Law - Orbits are conic sections with the center-of-mass of the two bodies at the focus.   Second Law - angular momentum conservation. <span style="font-size: 22pt; color: #7030a0; line-height: 115%; font-family: 'Wingdings 2'; mso-fareast-font-family: 'Wingdings 2'; mso-bidi-font-family: 'Wingdings 2'; msofareastfontfamily: 'Wingdings 2'; msobidifontfamily: 'Wingdings 2'; msolist: Ignore;">  Third Law - Generalized to depend on the masses of the two bodies.