When you wish to get away from it all, you probably should be careful where you wish to get. Far away, the sentiment usually is.

But “far away” is a doubtful phrase. Does it mean: “Away from the crowds”? Or: “Anyplace but here”? Or even: “Where no man (or woman) has gone before”?

People head for the wilderness in their SUVs to escape their everyday burdens, heartaches and troubles. But even deep in Baxter Park the sound of death-metal music and snowmobiles and other signs of beer-can civilization are never really distant.

Maybe “far away” means a place the human race has never been.

But there are few such spots on Earth. The jungles are filling up with skidders. More people are hiking to – and dying near – the tops of tall mountains. The oceans have been probed and measured, if not actually visited.

On Venus and Mars, and on Saturn’s and Jupiter’s moons, robots have landed. The Voyager spacecraft have rocketed past Uranus and Neptune, and their photos have been analyzed and humanized.

The only planet unsullied by close-up human contact is Pluto, named after the god of the dead. It’s far out there – averaging 40 Earth-sun distances (astronomical units, or AUs) away – and dark. At the moment, Pluto is the ultimate undiscovered country within imaginable view.

The idea of going there may inspire some dread, though. Pluto’s temperature is minus 400 degrees F. The sun is so far away that Plutonic day is little better than Earth night. It takes 248 years to orbit the sun once. At one point Pluto dips inside the orbit of Neptune; it just came out of its most recent dip in 1999 and is once again the most distant planet in the solar system. It’s so small and faint that it wasn’t detected until 1930. In 1978 a moon, Charon, was seen. Last year two smaller moons, Nix and Hydra, were spotted.

Pluto is about as far away as you can get and still feel awake enough, when you’re thinking about it, to imagine it’s real. And yet, there are farther, weirder places.

Beyond the edge of the solar system is the Kuiper Belt, which is a collection of small planetlike beings, roughly analogous to the asteroid belt between Mars and Jupiter except more dreamlike because so remote. About 1,100 Kuiper objects have been mapped. Quaoar and Varuna, for example, are so far away, 43 AUs, that no one really knows what they are at all.

Far beyond the Kuiper Belt is the Oort Cloud, thought to be the place where comets originate. In the desert places between the Kuiper Belt and Oort Cloud, even lonelier things are circling the sun. One, a reddish-colored sphere called Sedna, is now about 90 AUs away and looks as if its orbit carries it as far as 1,000 AUs from us. The most distant trans-Neptunian object so far seen has no name. It’s about the size of Pluto, and right now is 97 AUs away.

You would have to go to sleep, more or less permanently, to fly off to these empty spaces where no human presence is. What dreams might haunt such a sleep, and whether you’d ever return from it, should give pause. Maybe it’s better to just bear and overcome the everyday heartaches here, for as long as they last.