Astronomy Astronomy Celestial Mechanics and Orbits

Question 1

Which of Kepler's Laws states that planets sweep out equal areas in equal times?

Accepted Answer

Second Law (Law of Equal Areas)

Answer

Kepler's Second Law states that a line segment joining a planet and the Sun sweeps out equal areas during equal time intervals, meaning planets move faster when closer to the Sun.

Question 2

What is the eccentricity of a perfectly circular orbit?

Accepted Answer

0

Answer

A perfectly circular orbit has an eccentricity of 0, while values between 0 and 1 represent elliptical orbits, and values of 1 or greater represent parabolic or hyperbolic trajectories.

Question 3

What is the point in a planet's orbit where it is closest to the Sun called?

Accepted Answer

Perihelion

Answer

Perihelion is the point in a planet's orbit closest to the Sun; Earth reaches perihelion in early January each year at about 147 million km from the Sun.

Question 4

What is a Lagrange point?

Accepted Answer

A position where gravitational forces allow a small object to maintain a stable orbit

Answer

Lagrange points are five specific positions in a two-body orbital system where a smaller object can maintain a stable position due to the balance of gravitational forces.

Question 5

According to Kepler's Third Law, how does a planet's orbital period relate to its distance from the Sun?

Accepted Answer

The square of the period is proportional to the cube of the semi-major axis

Answer

Kepler's Third Law states that P² ∝ a³, meaning the square of a planet's orbital period is proportional to the cube of the semi-major axis of its orbit.

Astronomy Practice Test

Astronomy Practice Test

Astronomy Astronomy Celestial Mechanics and Orbits