With all the serious problems facing the world these days—wars, natural disasters, disease, not to mention the possibility of nuclear weapons in Iran and North Korea—you may not have noticed that the International Astronomical Union (IAU) recently decided to redefine the term “planet”.  Now Pluto, formerly the ninth planet in our solar system, is a “dwarf planet” along with the asteroid Ceres, and the recently discovered Eris.  No one from Earth is likely to travel to Pluto anytime soon, but when they do, and most people believe someone eventually will, they won’t mistake it for a normal planet.

Our interest in the neighboring planets and the stars beyond, of course, is driven by the quest for the answers to two fundamental questions.  How was the Universe formed?  And is there life, however basic, on other planets?  Knowing the answers to these two questions would tell us infinitely more about our own planet and about ourselves.  The scientific study of the Universe and the search for life, like all complex scientific issues, is the subject of debate among competing schools of thought, not the least of which is what constitutes a planet, hence the reclassification of Pluto.

Whether Pluto is a regular planet or a dwarf probably doesn’t make a big difference in the search for the origins of the universe or for life on other planets.  If there is life out there among the potentially billions and billions of planets, we likely won’t find it on a dwarf.  Then again, considering the prevailing scientific theory of how life started on earth—asteroids that struck earth during its formation carried the building blocks of life—studying dwarf planets like Pluto is as important as studying the planets themselves.

Our knowledge of the Universe has expanded exponentially in recent years.  Optical, infrared, and radio telescopes, deep space probes, Moon landings, rovers on Mars, and the analytical abilities computers provide us have allowed us to amass and analyze vast amounts of data.  It’s also provided fodder for more debates about everything from how black holes work and what purpose they serve to whether the Universe will ever stop expanding.  We haven’t found evidence for even the lowliest forms of life out there yet, but we keep trying.

The one thing that isn’t a matter of debate is just how far it is from one place to another in space and how many light years it takes to get to any place outside our solar system.  A light year, in case you’ve forgotten, is how far light will travel in one year at the speed of 186,282 miles per second.  Alpha Centauri, the closest star, is only 4.35 light-years away.  Distances to solar systems and galaxies beyond it boggle the mind.  The boundary of the observable universe is somewhere in the region of 15 to 20 billion light years away.

Given these distances, interstellar travel, in the context of the technology and physics we understand today, isn’t worth the effort if it’s not completely unachievable.  We’re not talking about the warp or hyperspace travel of Star Trek or Star Wars, but one-way journeys that would take hundreds of years, hardly a quest even the bravest of heart would be tempted to undertake for any reason short of escaping a dying planet Earth.

The dichotomy between the real Universe and the science fiction Universe, however, has never gotten in the way of our ability to imagine achieving what appears impossible.  Time and time again, that’s what has enabled man to turn the impossible into the possible.  Star Trek and Star Wars gave us hopeful visions of man’s future in outer space without the realities that would have undermined their visions. We watch the crew of the Starship Enterprise and the Jedi Knights travel from star system to star system with ease at speeds many times the speed of light.  There is no weightlessness and no time delay in communications across light years of space.  All the real limitations of interstellar travel simply don’t exist.  In our willing suspension of disbelief, we accept it.  What’s more, we believe it is a reality that man one day will actually achieve even if most aren’t willing to devote the resources necessary.

There was a time, a few short decades ago, when the launch of a manned space flight captured the attention of the entire world.  In a very short time, however, flights to the Moon, the launch of the Space Shuttle, and unmanned missions to Mars and the other planets became commonplace events.  Only when the inevitable disaster happens, like the Challenger accident of January 1986, does space flight once again become the focus of attention. 

Public support for the great expense of things like manned missions to Mars also has waned.  Is it really worth billions to put a couple of people on a desolate planet for a few weeks and return with a few buckets of rocks?  What will we learn that we can’t learn by sending an unmanned vehicle to land on Mars and retrieve those rocks?  Incidentally, you don’t have to go to Mars to get them.  Rocks dislodged from Mars by meteorites in the distant past fall to Earth all the time.

And if broad-based public support for funding a mission to Mars is lacking, who do you think will vote for the politician who proposes a one-way manned mission to a distant star system that no one living will be around to know if it was a success?

So if the reclassification of Pluto is an event you hardly noticed or care little about, that’s OK.  There are a lot more pressing issues to concern yourself with these days.  Pluto isn’t going anywhere for a very long time.  Neither, God willing, are the stars and galaxies.  They will be there waiting for our descendants whenever they get around to going there.  In the mean time they are reissuing the original Star Wars movies on individual DVDs.  If you don’t already own the box set, buy one, put it in your DVD player and enjoy it.  It’s the only way you are going to know what interstellar travel will be like several hundred years from now when it becomes a reality.