Here's the link to an interesting video showing the distribution of terrestrial vegetation on Earth. Two things were rather striking. First, notice just how green vast portions of the Earth aren't. The web site says green, green, green to describe these images, but man, lots of surface area is basically non-green, although even "bare" rock can habor algae & lichens (endolithic algae are pretty common - link to a western US study by a former student). Second, a nice segment shows the greening of North America from winter to summer. The first week of June is when the forest canopy is considered "complete" here in our latitude. Some other things to notice (some of which are pointed out) are the scars left by deforestation, fires, and cities. We're the only species whose activities can be seen from outer space. ET will notice them right away. TPP also likes trying to pinpoint where his study sites were located (mostly areas of pretty dark green).