What's lurking out there in the deep, dark regions of outer space?
Thanks to modern technology, we have a bit of an idea. But there's still some limits that we encounter.
As far as what we do know — we know there's lots of stuff out there beyond Uranus and Neptune. As touched on last week, there's Pluto, now categorized as a planet rather than dwarf planet ... and there are other objects, too, with a similar mass or smaller.
These objects all fall within what's called the Kuiper Belt, a region of space beyond the eight known major planets. The Kuiper Belt is between 30 and 55 astronomical units, or AU, away from the sun. (Remember, Earth is 1 AU, or 93 million miles, distant from the sun.)
Astronomers theorize a lot of rocky and icy objects lie within the Kuiper Belt, including some comets. It's been said that Pluto, or part of it, was perhaps part of a comet long ago. Either way, it is very much a planet now.
But the Kuiper Belt isn't all that lies beyond Neptune. For more than half a century, astronomers have theorized a large group of objects lies even farther from the sun. This region of space, called the Oort Cloud, is between 5,000 and 100,000 AU away from the sun — an astounding distance.
Here's where the limits of technology come into play. Five thousand AU is an extremely large distance — so distant, in fact, that astronomers believe we on Earth have never seen an object from that region of space. The Oort Cloud likely consists of billions — perhaps even a trillion — of icy bodies so far out from the sun, that they barely belong to our solar system. Astronomers believe that these bodies never exit the Oort Cloud unless they were to be flung into the inner solar system by a passing star, or under the influence of some other object.
If we were lucky enough to see an object from the Oort Cloud, we would only see it once, never to be seen again.
Of course, maybe there are bigger things out beyond Pluto ... another planet, perhaps? Who knows what we may find.
Joe Malan attended Valparaiso University from 2004-08, where he conducted observatory and planetarium shows for the public. Email him at email@example.com.