These spores came from a black mold I found on an orange that had been in my refrigerator for way too long. I didn't notice it until after I had already peeled it. Being ever resouceful, I saw this an an oppurtunity and put some of it under the microscope.
Like pollen grains,
mold spores are extremely small and light
and can float in the air buffeted about by tiny currents. They can remain aloft for a long time and thus be spread over a large
area. When caught in thermal updrafts, they can spread all over the world. If spores reach a high enough
altitude, it is possible that repulsion from the earth's magnetic field may cancel out the effect of
gravity and they could drift into space. Since they can survive for millions of years, it is possible
that some may land on another planet and find the right conditions to grow. Once the mold becomes
established its spores would rapidly spead over the
new planet. It is possible then, that some earth
fungi may even now be growing on another planet and some of our
fungi, or their ancestral forms, may have
It should be pointed out that it has not yet been proven that spores are reaching outer space, "needle in a haystack" does not even begin to describe the difficulty involved in detecting them there, but there is no good reason why this couldn't happen.