Want to stay on top of all the space news? Follow @universetoday on Twitter
You probably know by now that Pluto has already been ‘demoted’ from being a planet. Right now, it is classified as a KBO or a Kuiper Belt Object. Obviously, a KBO is an object found in the Kuiper Belt … but what is the Kuiper Belt? Is it like the asteroid belt?
Kuiper Belt is a region in space initially predicted by astronomer Gerard P. Kuiper. Now, this was way back in 1951. It took more than four decades before the said region was finally discovered. In fact, it took five years of searching before David Jewitt and Jane Luu were finally successful.
Well, you can say that there are similarities between Kuiper Belt and the asteroid belt, both being composed of celestial objects. But Kuiper is much much larger – about 20 times wider and perhaps 200 times more massive.
Also, while the asteroid belt is composed mainly of asteroids and meteoroids, which are basically made up of rock and metal, Kuiper is made up of frozen volatiles (methane, ammonia, and water). That’s right, the objects there are pretty much like comets.
Now, how did a “planet” like Pluto get to be reclassified into a KBO? First, Pluto is found right inside Kuiper. Furthermore, there are lots of objects in there that are pretty much of the same size (only slightly smaller actually) as Pluto. Finally, there are objects outside (but near) Kuiper that are larger than Pluto.
One of these objects is Eris, which is estimated to be 27% more massive than Pluto. Another object which is larger than Pluto and also believed to have been once a KBO is Triton, Neptune’s natural satellite.
We’ve mentioned earlier that most of the objects found in Kuiper have similar composition to those of comets. It would be therefore tempting to conclude that Kuiper and the Oort cloud are one. The Oort cloud is a hypothetical region believed to be the “dwelling place” of comets.
Scientists however think the Oort cloud is much much farther away. While the Kuiper Belt is in the region between 30 AU to 55 AU from the Sun, the Oort cloud is believed to be 50,000 AU from the Sun. That’s nearly one light-year away.
A deeper understanding of Kuiper should emerge once the spacecraft New Horizons reaches Pluto in July 2015. New Horizons was launched on January 19, 2006 for the purpose of exploring the Kuiper Belt.
We’ve got a couple of interesting articles here in Universe Today that talk about Kuiper:
Here are some more fascinating articles and images from NASA:
How about letting your ears do the work for a change? Check out this podcast at Astronomy Cast: