Have we mentioned that January is Science Fiction Month? We have? Well, here's an idea to get your creative juices flowing. GregPius has kindly donated this storyboard. Just write your version, and post it on the The New h2g2 Science Fiction Workshop. See you over there!
No One Home
When the aliens finally arrive on Earth they are surprised at the lack of any sort of welcome. When orbiting the planet they had clearly seen signs of artificial structures.
Imagine their surprise when no large life forms are found on the Earth's surface. Soon they determine that the Earth must be a ghost planet. Even when caves and discernible hiding places are probed thoroughly, no new discoveries are made. Yet the fossil record clearly indicates large life forms had covered the Earth's surface. Finally some large life forms are found deep in the oceans near the poles.
The scientists with the alien expedition, after taking soil and air samples, finally come up with possible solutions. They had already noted the large holes in the ozone layer. Air quality tests come back with toxic readings. Water samples showed that some toxic substance has entered the ecosystem.
As the aliens prepare to leave Earth for good, they theorize over a number of alternate explanations. Finally they agree to disagree and shelve their curiosity. Giving Earth one last look in orbit, the aliens think sad thoughts. And then they are gone from the Solar System.