Fire on Earth

Sometimes, regions of planet Earth light up with fire.

Since >fire is the rapid acquisition of oxygen, and since
oxygen
is a key indicator of life,
fire
on any planet would be an indicator of life on that planet.

Most of the Earth’s land has been
>scorched by fire at some time in the past.

Although causing many a tragedy,
for many places on Earth
fire is considered part of a
>natural ecosystem cycle.

Large >forest fires on Earth are usually caused by
lightning and can be
>visible from orbit.

>Above, in the year 2000, stunned
>elk avoid a
fire sweeping through
Montana‘s
Bitterroot Valley
by standing in a river.

Credit:
(AFS,
BLM)