Precession, Nutation & Barycenter

Earth's orbit follows an elliptical path.

• Kepler's 1st law
• Kepler's 2nd law
• Kepler's 3rd law
• Nutation

When Earth orbits around the sun, it slows down when it is close to the sun. It speeds up its orbit when it is further from the sun. This is because the sun's gravity is stronger when you are closer to it.

• Kepler's 1st law
• Kepler's 2nd law
• Kepler's 3rd law
• Nutation

Planets further from the sun have an orbit that lasts MUCH longer than planets that are close to the sun.
Pluto's orbit lasts over over 90,000 days.
Mercury's orbit lasts 88 days.

• Kepler's 1st law
• Kepler's 2nd law
• Kepler's 3rd law
• Nutation

The Earth's axis changes direction (but the angle does NOT change).

• Nutation
• Precession
• Barycenter
• Revolution

During precession, the Earth wobbles a little. This DOES change the angle of the axis.

• Nutation
• Precession
• Barycenter
• Revolution

Where does nuclear fusion occur with the sun?

• Space

• Radiation Zone

• Photosphere

• The Core

The energy from the sun is created by a process called:

• nuclear fission
• nuclear fusion
• nuclear reaction
• nuclear core

What protects life on Earth from gamma rays, X rays, and particles emitted by the Sun?

• The ozone layer in the stratosphere
• The ionosphere
• The magnetosphere (Earth's magnetic field)
• Clouds

Slow, circular movement at the top of Earth's axis

• precession
• barycenter
• revolution

A wobble back and forth

• Rotation
• Nutation
• Revolution