Kepler's First Law of Planetary motion

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What is Kepler's First Law of Planetary Motion?

Back

Kepler's First Law states that planets move in elliptical orbits with the Sun at one of the foci.

Front

What is the semi-major axis in an ellipse?

Back

The semi-major axis is half the longest diameter of an ellipse, representing the average distance between a planet and the Sun.

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What is perihelion?

Back

Perihelion is the point in a planet's orbit where it is closest to the Sun.

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What is aphelion?

Back

Aphelion is the point in a planet's orbit where it is farthest from the Sun.

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What does eccentricity measure in an orbit?

Back

Eccentricity measures the deviation of an orbit from being circular; it ranges from 0 (circle) to 1 (parabola).

Front

What is the eccentricity of a circle?

Back

The eccentricity of a circle is 0.

Front

What is the significance of the foci in an elliptical orbit?

Back

In an elliptical orbit, one focus is occupied by the Sun, and the other focus is empty; this affects the shape and dynamics of the orbit.

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How do you calculate the eccentricity of an ellipse?

Back

Eccentricity (e) = distance between foci / length of the major axis.

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What is the relationship between the semi-major axis and the orbit's period?

Back

According to Kepler's Third Law, the square of the orbital period is proportional to the cube of the semi-major axis.

Front

What is the term for the longest diameter of an ellipse?

Back

The longest diameter of an ellipse is called the major axis.