If this is the only planet on which not only life, but intelligent life, has arisen, that would be very unusual.

The number of habitable worlds in our galaxy is certainly in the tens of billions, minimum, and we haven't even talked about the moons. And the number of galaxies we can see, other than our own, is about 100 billion.

If this is the only planet on which not only life, but intelligent life, has arisen, that would be very unusual.

Despite the impression you may have from watching too much TV, movies are not about reproducing reality. Theyre about telling stories.

There is a point of view among astronomical researchers that is generally referred to as the Principle of Mediocrity. ... If the Sun and its retinue of worlds is only one system among many, then many other systems will be like ours: home to life. Indeed, to the extent that this is true, we should be prepared for the possibility that, even in the Milky Way galaxy, billions of planets may be carpeted by the dirty, nasty business known as life.

Five centuries from now - barring unimaginable catastrophe - the moon will be developed real estate. There's economic incentive to exploit the moon - the helium-3 will be useful in powering fusion reactors, and the rare earth elements could supplant the limited terrestrial supply of these materials.

There is little chance that aliens from two societies anywhere in the Galaxy will be culturally close enough to really 'get along.' This is something to ponder as you watch the famous cantina scene in Star Wars. ... Does this make sense, given the overwhelmingly likely situation that galactic civilizations differ in their level of evolutionary development by thousands or millions of years? Would you share drinks with a trilobite, an ourang-outang, or a saber-toothed tiger? Or would you just arrange to have a few specimens stuffed and carted off to the local museum?