# Moon Day

I like to challenge the brain on a regular basis. Now I’m going to challenge your brain. Don’t look up the answer on the internet right away, this is a private process for your brain only.

True or False: The nearest earth type planet discovered by humans is only 4 light years away.

Think about that for a minute. Four light years, if we could travel the speed of light, would take, well, four years to reach (at a speed of 186,000 miles per *second, *or seven times around the diameter of the earth). If we could go ten times the speed of light, it would still take more almost five months (speed of 1,860,000 miles per *second*). It takes eight minutes for the light of our sun to reach the earth. Four light years is pretty far away. At 17,000 mph, the current average space shuttle speed, it would take 165,000 years to reach a planet 4 light years from here.

And the truth is the closest earth-like planet discovered is 11.9 light yeas away around the sun-like star Tau Ceti. Now triple all the figures above. Half a million years to get there with today’s technology? That’s the disappointing fact. Even a generational ship is a pretty far stretch of the imagination. And yet we still dream of discovering life on other planets, shaking hands with extra terrestrials, or at least finding an amoebae we can bring home in a Petri dish. So what do we do?

We keep hunting nearby, we keep studying whatever we can, and we don’t stop reaching for the stars.