Beyond the orbit of the outer giants, beyond the orbit of Pluto even is a region of the solar system is the Kuiper belt. A place where the material left over from the creation of the solar system resides. We’re not quite into interstellar space (the space between the stars) yet, in fact we’re not totally sure where that begins yet. The Voyager probes that are the farthest human object from Earth are helping us to find this out.
The Kuiper belt isn’t a single object, it’s many object forming a ring around the sun from the orbit of Neptune’s e (30AU’s) to 50 AU’s from the sun. It’s in this belt that frozen comets, and icy dwarf planets are made. Pluto and Neptune’s moon Triton are thought to be Kuiper belt objects, captured and brought nearer to the sun. But what else do we know is out there?
The Kuiper belt is known to be the region of a number of Dwarf planets:
Are the main bodies, but other smaller object such as Ixion, Varuna and Orcus are continually being discovered. Pluto is also now classified as a dwarf planet and a Kuiper belt object and Neptune’s moon Triton is suspected to be a large Kuiper belt object that was captured by Neptune’s gravity as it orbits Neptune the wrong way. Triton is made up in a very similar way to Pluto to give further weight to this theory.
Voyager 2’s flyby in 1989 made discoveries of volcanoes or frozen methane and details on terrains which up until then we didn’t know existed. It was our first glimpse of what a Kuiper belt object was.
New Horizon’s flew past Pluto on 15th January 2015. The historic encounter brought back images and data of a world which up until then was almost completely unknown. p until then Pluto and it’s largest moon Charon had merely been a small and detail-less point of light in even the most powerful telescope.
There was always the possibility that New Horizons would be used to explore other Kuiper belt objects. Now it has been granted it’s second mission and New Horizons has been steered to make a close encounter with the rather unromantically named 2014 MU69 on January 1st 2019.
This will be the furthest object ever encountered by a human spacecraft to date at over 43 times the distance the Earth is from the Sun. What we will find is a mystery, it might be another ball of frozen gas, rock and ice or something completely different. Either way it will give us more information about what is in the Kuiper belt.
The Kuiper belt is a long, long way off and it takes a long time to get there. Any future missions are going to have to overcome this problem and justifying going out there is another problem. This is why New Horizons is the first and only probe to go out there and look at anything. Maybe we can look at more before New Horizons speeds out of the solar system. But in the meantime, advances with space telescopes mean we’re getting much more data that we ever have been before.
Hubble was used to plan the New Horizons flyby of Pluto, looking for other moons that needed to be avoided. Hubble found a small handful, handy to know when you’re shooting long distance like that. Dwarf planets in the Kuiper belt are giving up more of their secrets and revealing moons – There’s a whole solar system out there!