Which generation of humans will spend the trillions of dollars to launch a ship whose success of failure will not be reported for centuries? And unless human lifespans dramatically increase, the crew of such a ship may well be robots. So what is the reality of exploration out of our own solar system?

We walked on the moon almost 50 years ago. And nearly one half century later, no human has stood on another planet. Yes, it seems we may get to Mars in another decade, but we’re pretty sure those first Martians won’t be coming back home. There’s no plan for that.

I’m all for space exploration, I really am. But when will exoplanet exploration become a reality? Five hundred years? A thousand years? Longer? Hard to know.

This visual essay was produced for and included in the interactive project 7 Amazing Exoplanets which can be viewed at Scientificamerican.com.

• Written and narrated by Ed Bell
• Animation by NASA/JPL, ESO, Tom Miller and Ed Bell
• Illustrations by Ron Miller, NASA, ESA, G. Bacon (STSCI)
• Music by Kostas Varotsis