New Horizons takes first images of Ultima Thule
From a distance of more than 100 million miles (160 million kilometers) and against a background filled with stars, New Horizons‘ Long Range Reconnaissance Imager (LORRI) took the first images of its second target, Kuiper Belt Object (KBO) Ultima Thule.
Taken Aug. 16, 2018, the 48 images forming the resulting composite image of the KBO were returned through NASA’s Deep Space Network. Mission scientists had expected the first LORRI image of Ultima Thule to be taken in September. Between now and its 2019 New Year’s Day flyby of Ultima Thule, New Horizons is expected to observe its target many times in order to refine the spacecraft’s closest approach.
LORRI’s detection of Ultima Thule indicates the KBO is in the exact location mission scientists expected it to be based on observations from the Hubble Space Telescope. That data has also enabled teams to calculate the object’s orbit.
“The image field is extremely rich with background stars, which makes it difficult to detect faint objects,” said New Horizons project scientist and LORRI principal investigator Hal Weaver of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, in a NASA news release. “It really is like finding a needle in a haystack. In these first images, Ultima appears only as a bump on the side of a background star that’s roughly 17 times brighter, but Ultima will be getting brighter—and easier to see—as the spacecraft gets closer.”
New Horizons principal investigator Alan Stern of the Southwest Research Institute in Boulder, Colorado, praised the mission team for working hard to determine whether LORRI had succeeded in locating tiny Ultima Thule from so far away.
“We now have Ultima Thule in our sights from much farther out than once thought possible,” Stern said. “We are on Ultima’s doorstep, and an amazing exploration awaits.”
Closest approach is expected to occur at 12:33 a.m. EST (04:33 GMT) Jan. 1, 2019. Should all go according to plan, Ultima Thule will become the most distant object ever visited by a spacecraft. The previous record was also set by New Horizons when it flew by Pluto in July 2015. The much smaller KBO is located approximately one billion miles (1.6 billion kilometers) beyond Pluto.
Other records set by the spacecraft include it having taken the furthest ever image of the Sun and the furthest ever images from Earth. Captured in December 2017, the latter depicted the “Wishing Well” open star cluster and other remote KBOs.
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.