Ultima Thule

The Kuiper belt object Ultima Thule, about 1 billion miles beyond Pluto, encountered by the New Horizons spacecraft on Jan. 1, 2019.

New York Times - A Sharper Picture of Ultima Thule From NASA’s New Horizons
By Kenneth Chang
Jan. 25, 2019

The icy rock that NASA’s New Horizons spacecraft flew past on New Year’s Day is coming into focus.

On Thursday, the mission team released the sharpest picture of the 21-mile-long body known officially as 2014 MU69 and nicknamed Ultima Thule. Consisting of two roundish lobes that are fused together, it is believed to be an almost pristine leftover from the earliest days of the solar system, more than 4.5 billion years ago.

[Sign up to get reminders for space and astronomy events on your calendar.]

The spacecraft took the picture when it was 4,200 miles from Ultima Thule, just seven minutes before its closest approach. From this angle, the shadows are more apparent, revealing a deep depression on the smaller lobe. This could be a crater, a pit that collapsed or an area that was blown out when gases escaped from the interior long ago.

Scientists also can better resolve light and dark patterns on the surface, including a particularly bright collar where the two lobes connect.

Even sharper pictures could be sent back to Earth in the coming weeks as the spacecraft travels further into the distant solar system. New Horizons will continue to stream data from the flyby until late 2020.

Earlier reporting on the New Horizons flyby of Ultima Thule

What We’ve Learned About Ultima Thule From NASA’s New Horizons Mission Jan. 3, 2019

Snowman-like Photo of Ultima Thule Sent Home by NASA’s New Horizons spacecraft Jan. 2, 2019

NASA’s New Horizons Takes Photos of Ultima Thule, 4 Billion Miles AwayDec. 31, 2018

A Journey Into the Solar System’s Outer Reaches, Seeking New Worlds to Explore Dec. 30, 2018


Kenneth Chang has been at The Times since 2000, writing about physics, geology, chemistry, and the planets. Before becoming a science writer, he was a graduate student whose research involved the control of chaos. @kchangnyt

A version of this article appears in print on Jan. 28, 2019, on Page D2 of the New York edition with the headline: Light and Dark: 4.5 Billion Years Old, Coming Into Focus. Order Reprints | Today’s Paper | Subscribe