Kepler's Laws of Planetary Motion

Which astronomer’s observations of the planet Mars were used by Kepler to formulate his laws of planetary motion?

• Tycho Brahe

• Galileo Galilei

• Edwin Hubble

• Nicholas Copernicus

The diagram shows the orbit of a comet around the Sun. X marks the point at which the comet is furthest from the Sun. What is the name of point X?

• Aphelion

• Apogee

• Perigee

• Perihelion

Which of the following statements is correct?

• A planet has its largest speed when it is close to aphelion.

• A planet has its largest speed when it is close to perihelion.

Which of the following has the largest eccentricity?

• A

• B

• C

• D

Which planet below has the smallest variation in orbital speed?

• Earth

• Venus

• Jupiter

• Neptune

Which is the correct formula relating orbital period (T) and mean radius (r)?

• $T\propto r$

• $T\propto r^2$

• $T^2\propto r^2$

• $T^2\propto r^3$

Which statement below is correct?

• The greater a planet's distance from the Sun, the longer its orbital period.

• The greater a planet's distance from the Sun, the shorter its orbital period.

The International Space Station orbits the Earth once every 90 minutes. How many minutes does it take the ISS to travel from apogee to perigee?

• 90

• 45

• 30

• 180