The Structure of Comets

identify the nucleus, coma, dust and ion tails of comets
demonstrate an understanding that the tails of comets develop when relatively close to the Sun
demonstrate an understanding of the mechanisms for the development of cometary dust and ion tails

Comets are made up of a mixture of frozen water, gases and dust like dirty muddy ice balls. They are the remains of material that was left over after the formation of the solar system.

Comets are only visible when they are near the Sun in their very eccentric orbits. Their orbits are often tilted to the ecliptic and retrograde.


The main components of a comet are:

The Nucleus - ice, dust and small rocky particles from a few km to 10s of km in size

The Coma - a visible fuzzy atmosphere

The Dust Tail - a long tail of dust which reflects sunlight. Often curved as the parts further from the Sun orbit slower

The Ion Tail - always points away from the Sun as it is more affected by solar wind

The solar wind blasts material off the comet leaving a visible dust tail. After 500 or so orbits the gas and water may have been blasted off and all that remains is the rocky nucleus, the comet is dead.