Blue Sky Science: What is the Kuiper belt?

Piper Hirsch


What is the Kuiper belt?

The Kuiper belt, named after astronomer Gerard Kuiper, is a massive, icy region of our solar system that exists just beyond the planets. Actually shaped more like a donut than a flat belt, the Kuiper belt is best known as home of the dwarf planet Pluto.

The New Horizons mission promises to give us much better pictures of this region. When Pluto’s moon, Charon, was discovered in 1978, it looked like just a smudge —we could not separate Charon’s image from Pluto’s image. And now we can see them clearly separated in the New Horizons images, and we expect to get much better pictures from that mission.

One of the most striking pictures was actually of Charon. It’s got canyons and valleys that are several miles deep. Who would have thought that would exist on a moon so far away. Even our moon doesn’t have as much geology as Pluto and Charon do.

Objects within the Kuiper belt, outside of Pluto, have only been discovered in the last two to three decades. We have observed dark patches on Pluto that seem to correlate with the presence of methane. That’s likely to be common element in Kuiper Belt objects.

So we can expect that other Kuiper Belt objects, should we get a chance to visit them up close, may end up looking a lot like Pluto. But Pluto has given us so many surprises, we have no idea what to expect. That’s the thing about exploration — we can always be surprised.