According to the New Horizons’ twitter feed, @NewHorizons2015, and Principal Investigator Alan Stern, the New Horizons probe will make a long-range encounter with a Kuiper Belt Object in January 2015. The object is temporarily designated VNH0004 by the mission team. It does not yet have an International Astronomical Union designation.
The encounter will take place at a range of about 75 million km, a distance somewhat subject to change depending on how the probe makes its course correction.
At such a great distance, New Horizons will not be able to discern features on the surface of the KBO, nor will it be able to make spectroscopic observations to try to determine the composition of the surface material.
However, New Horizons will be in an excellent position to look for small, close-in moons around the object. It will also be in a position to observe the object’s phase curve, which is a measure of how the reflectivity of the surface changes as a function of viewing angle. This will reveal a great deal about the fluffiness of the surface material (note – fluffiness is a technical term meaning, roughly, “the opposite of dense”). These two observations cannot be made from Earth, even with the most powerful telescopes available.
But this will not be the only KBO encounter planned for New Horizons. The mission team expects three such distant encounters in 2015, this one in January, and two others in June and September.
In fact, mission planners hope to have at least three such encounters every year from 2015 to 2018.
The team also hopes to have one close-up flyby of another KBO after its Pluto encounter in July (corrected) of 2015.