So the star we are seeing is really how the star looked a million years ago, not how it looks today. In the same way, our sun is 8 or so light minutes away. If the sun were to suddenly explode right now, we wouldn’t know about it for eight minutes because that is how long it would take for the light of the explosion to get here.

186,000 miles/second * 60 seconds/minute * 60 minutes/hour * 24 hours/day * 365 days/year = 5,865,696,000,000 miles/year

A light year is 5,865,696,000,000 miles (9,460,800,000,000 kilometers). That’s a long way!

Even if we are able to travel in light year, we’ll spend most of our life in the spaceship. Teleport is the only way.

Link: http://edition.cnn.com/2009/TECH/12/16/super.earth.discovery/index.html