NASA’s New Horizons spacecraft’s next target is 2014 MU69 and nicknamed PT 1 or “potential target 1,” the U.S. space agency announced afternoon. A spacecraft that made a historic flyby of Pluto in July has a new destination, an frigid rock that may reveal what the outer solar system was like shortly after it formed 4.6 billion years ago.
The mysterious icy object is less than 45 kilometres across, a tiny fraction of the size of Pluto, which is 2,370 kilometres wide. PT 1 is 1.6 billion kilometres farther away than Pluto, which was itself 4.7 billion kilometres from Earth when the spacecraft flew by. Both Pluto and PT 1 are in an outer region of the solar system known as the Kuiper Belt, which contains thousands of icy objects, some very small and others that are large enough to be considered dwarf planets, such as Pluto.
New Horizons will begin changing direction to target PT 1 in late October or early November and is expected to arrive on New Year’s Day 2019. If all goes well, it’ll take measurements and detailed images of a type of celestial object that has never been seen before.
“There is so much that we can learn from close-up spacecraft observations that we will never learn from Earth, as the Pluto flyby demonstrated so spectacularly,” said New Horizons science team member John Spencer of the Southwest Research Institute in Boulder, Colo.
Unlike Pluto, which shows signs of geological activity and an actively changing surface with characteristics such as flowing glaciers, PT 1 is thought to have been deep frozen since its formation. Small objects like PT 1 are thought to be the building blocks that formed Kuiper Belt dwarf planets like Pluto. PT 1 was one of five discovered using the Hubble Space Telescope in 2014. The list was later narrowed down to two that were close enough to the spacecraft’s flight path.
Alan Stern said, PT 1 was chosen because New Horizons did not need as much fuel to get there, leaving more fuel for the flyby itself, for scientific measurements, and as a backup in case of unforseen circumstances, principal investigator of the New Horizons mission.