gcsescience.com 24 gcsescience.com
Comets.
Like
planets,
comets orbit the Sun.
Unlike a planet, the orbit of
a comet is often highly elliptical
and may be very, very long.
A comet can only be seen when it is near
our Solar system, close to the
Sun.
At other times the comet is
too far away.
The speed of a comet
changes during its orbit.
As the comet gets closer to the Sun,
the Sun's gravity pulls the comet
towards it and the comet
gets faster.
Also, the gravitational forces become stronger as the comet gets
closer.
The comet is travelling at its fastest when it is closest to the Sun.
As the comet moves away from
the Sun, the reverse happens.
The Sun's gravity pulls the comet
backwards and slows it down.
The gravitational forces become weaker
as the comet gets further away.
The comet is travelling at its slowest when it is furthest from the Sun.
In energy terms, the
movement of the comet is similar
to a swinging pendulum or
bouncing ball.
When the comet is closest to the Sun,
it has its maximum kinetic energy
and minimum gravitational potential energy.
When the comet is furthest
from the Sun, it has its minimum kinetic energy
and maximum gravitational potential
energy.
Headings
The
Earth and Beyond Search Questions
gcsescience.com Contents Index Quizzes gcsescience.com
Copyright © 2008 Dr. Colin France. All Rights Reserved.