April 6th, 2017
NASA’s New Horizons spacecraft reached the halfway point between Pluto and its second , KBO 2014 MU69, at midnight UTC on Monday, April 3 (8:00 p.m. EDT on Sunday, April 2) at a distance of 486.19 million miles (782.45 million kilometers) from Pluto and the same distance to MU69.
Just a few days later, at 21:24 UTC (5:24 p.m. EDT) on April 7, the spacecraft will reach the midpoint in time between its 11:48 UTC (7:48 a.m. EDT) July 14, 2015, closest approach to Pluto and its predicted 06:00 UTC (2:00 a.m. EDT) closest approach to MU69 on January 1, 2019.
Five days separate the midpoint in distance from the midpoint in time because the Sun’s gravitational pull is slowing down the spacecraft, which is pulling away from the Sun’s gravity.
Even with the slowing, New Horizons is speeding through the Kuiper Belt at 32,000 miles (51,500 kilometers) per hour.
“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,” noted mission Principal Investigator Alan Stern of the Southwest Research Institute in Boulder, Colorado.
New Horizons’ Long Range Reconnaissance Imager () will begin observing MU69 this September.
For the first time since December 6, 2014, the spacecraft will go into hibernation, a state in which it will remain for 157 days.
The Pluto flyby and 16-month return of data taken at Pluto meant that New Horizons had to be “awake” for two-and-a-half years.
While awake, its instruments also conducted distant observations of 12 KBOs, studied dust and charged particles in the Kuiper Belt, and analyzed hydrogen gas in the heliosphere – a large region of space around the Sun through which the solar wind extends and the Sun exerts magnetic influence.
New Horizons’ position can be seen at any time at this website .
Project scientist Hal Weaver of APL in Laurel, Maryland, said that the spacecraft will conduct distant studies of more than 24 additional KBOs as well as measure dust and charged particles in the environment throughout its continuing Kuiper Belt journey.
With 3.5 billion miles (5.7 billion kilometers) between Earth and the spacecraft, communication at the universal speed of light takes about five hours and 20 minutes each way.
Laurel Kornfeld is an amateur astronomer and freelance writer from Highland Park, NJ, who enjoys writing about astronomy and planetary science. She studied journalism at Douglass College, Rutgers University, and earned a Graduate Certificate of Science from Swinburne University’s Astronomy Online program. Her writings have been published online in The Atlantic, Astronomy magazine’s guest blog section, the UK Space Conference, the 2009 IAU General Assembly newspaper, The Space Reporter, and newsletters of various astronomy clubs. She is a member of the Cranford, NJ-based Amateur Astronomers, Inc. Especially interested in the outer solar system, Laurel gave a brief presentation at the 2008 Great Planet Debate held at the Johns Hopkins University Applied Physics Lab in Laurel, MD.