The mission’s first encounter will give scientists a glimpse at what the early disk of our solar system may have looked like.
The Kuiper Belt extended mission is funded through 2021, with team members of New Horizons working to plan flight trajectories and image mapping sequences for multiple encounters with distant—possibly exotic—objects.
At midnight CST on January 1, 2019, the New Horizons spacecraft will whizz past a distant, reddish planetoid 2014 MU69. The object is an intermediary between comets and small planets, and is about 1,000 times more massive than 67P, the comet explored by the Rosetta mission. The Kuiper Belt object 10,000 times less massive than Pluto.
“We will flyby 2014 MU69 at very close range, much closer than we did with Pluto,” said Alan Stern, New Horizons Mission principal investigator.
The encounter with MU69 is the first of multiple encounters, according to Amanda Zangari, co-investigator of the Kuiper Belt extended mission.
Twenty-five encounters are planned to put MU69 within proper context, and the team will use the onboard instruments to measure the dust and plasma levels of the Kuiper Belt’s atmosphere over the span of nearly 2 billion miles. At its most distant point, New Horizons will study an area nearly 50 astronomical units from the Sun, over 4.6 billion miles.
A few times each year, the team studies MU69’s position with the Hubble Space Telescope to adjust the timing and position of the spacecraft along its journey. The minor adjustments will allow New Horizons to get into range for the sequence of instructions to execute during the planned first encounter.
“The next two years here on Earth is going to be very busy with encounter planning,” Zangari said. “We are outlining science goals, which allows us to decide what observations will meet those objectives, then prioritize the types of observations we make. From there, we can write, test and refine the set of spacecraft instructions—called a command load—the spacecraft will execute during the encounter. At 2014 MU69, communications we send to the spacecraft take 6 hours to get there, so we can’t do anything in real time.”
Through studying the object, its apparent redness was discovered through using filters on Hubble’s camera to study the intensity of sunlight reflecting off of MU69 back to Earth. The data was then compared to measurements in different filters to study red and infrared light.
“MU69 is redder than Pluto and the Sun, but not nearly as red as Mars,” Zangari added.
The planned close encounter will allow the team to study the composition of the distant reddish object, how it rotates; study the topography of its surface; map its collision history and search for signs of escaping dust or gas.
“These flybys are something we’ve hoped to do all along,” Zangari said. “So, it’s an added bonus, but it’s been there from the very beginning.”
Objects from the distant neighborhood are believed to have formed in relatively the same location the objects occupy currently. The belt consists of the remnants at the edge of the disk in which the contemporary planets formed.
The objects are not controlled by the massive orbit of Neptune, like Pluto is, and maintain highly eccentric, inclined orbits—meaning gravity or a collision moved them from where they originally formed.
With the success of New Horizons and learning of Pluto’s exotic geological activity; internal heat source and a possible subsurface ocean; the discoveries made on Pluto completely changed the scope of the extended mission, and how the team might study the distant objects.
“There are several other objects out there in the Kuiper Belt that are about as big as Pluto, or nearly as big as Pluto,” said John Spencer, New Horizons geology team leader and extended mission planner. “So, the fact that Pluto has all of these exotics going on makes us rethink our picture of these other objects. Some of these other objects could be similarly exotic when we can get to them and see them close up.”
Dr. Amanda Zangari serves as the co-investigator on the New Horizons Kuiper Belt Extended Mission. She assists with selecting the mapping of star fields ahead of the Kuiper Belt object encounters.