https://www.nasa.gov/feature/new-horizons-halfway-from-pluto-to-next-flyby-target
Continuing on its path through the outer regions of the solar system, NASA’s New Horizons spacecraft has now traveled half the distance from Pluto –
its storied first target – to 2014 MU69, the Kuiper Belt object (KBO) it will fly past on Jan. 1, 2019. The spacecraft reached that milestone at midnight
(UTC) on April 3 – or 8 p.m. ET on April 2 – when it was 486.19 million miles (782.45 million kilometers) beyond Pluto and the same distance from MU69.
“It’s fantastic to have completed half the journey to our next flyby; that flyby will set the record for the most distant world ever explored
in the history of civilization,” said Alan Stern, New Horizons principal investigator from the Southwest Research Institute in Boulder, Colorado.
Later this week – at 21:24 UTC (or 5:24 p.m. ET) on April 7 – New Horizons will also reach the halfway point in time between closest approaches to Pluto,
which occurred at 7:48 a.m. ET on July 14, 2015, and MU69, predicted for 2 a.m. ET on New Year’s Day 2019. The nearly five-day difference between the halfway
markers of distance and time is due to the gravitational tug of the sun. The spacecraft is actually getting slightly slower as it pulls away from the sun’s
gravity, so the spacecraft crosses the midpoint in distance a bit before it passes the midpoint in time.
