xi's moments
Home | Americas

NASA's New Horizons unravels mysteries of Ultima Thule

Xinhua | Updated: 2019-03-19 10:10

Ultima Thule, 20-mile-long (32-km-long) space rock, taken by NASA's New Horizons spacecraft, taken at 5:01 GMT on Jan 1, 2019, just 30 minutes before closest approach from a range of 18,000 miles (28,000 kilometers), is shown in this image released by Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, USA, on Jan 2, 2019. [Photo/Agencies]

LOS ANGELES -- NASA's New Horizons mission team on Monday unraveled mysteries of the Kuiper Belt object (KBO) nicknamed Ultima Thule, the most distant object ever explored by mankind.

New Horizons performed the farthest flyby in history at 12:33 am EST (0533 GMT) on New Year's Day, as it approached Ultima Thule within 2,200 miles (about 3,540 km) of the surface at a velocity of 31,500 miles (about 50,694 km) per hour.

Analyzing the data New Horizons has been sending home since the flyby, mission scientists are learning more about the formation, geology and composition of this ancient relic of solar system formation, said a NASA release.

Ultima Thule is the first unquestionably primordial contact binary ever explored, said the mission team. Approach pictures of Ultima Thule hinted at a strange, snowman-like shape for the binary, but further analysis of images taken near closest approach uncovered the object's unusual shape.

Ultima Thule consists of a large and flat lobe (nicknamed "Ultima") connected to a smaller and rounder lobe (nicknamed "Thule").

"We've never seen anything like this anywhere in the solar system," said New Horizons Principal Investigator Alan Stern. "It is sending the planetary science community back to the drawing board to understand how planetesimals - the building blocks of the planets - form."

Scientists believe Ultima Thule's two lobes once orbited each other, like many so-called binary worlds in the Kuiper Belt, until something brought them together in a "gentle" merger.

The "neck" connecting Ultima and Thule is bent, and could indicate shearing as the lobes combined, said Kirby Runyon, a New Horizons science team member.

In terms of color and composition, Ultima Thule is very red - redder even than Pluto, which New Horizons flew past on the inner edge of the Kuiper Belt in 2015, and about the same color as many other so-called "cold classical" KBOs, said the team.

New Horizons scientists have also seen evidence for methanol, water ice and organic molecules on the surface.

Currently the New Horizons spacecraft is 4.1 billion miles (6.6 billion kilometers) from Earth, operating normally and speeding deeper into the Kuiper Belt at nearly 33,000 miles (53,000 kilometers) per hour.

Global Edition
BACK TO THE TOP
Copyright 1995 - . All rights reserved. The content (including but not limited to text, photo, multimedia information, etc) published in this site belongs to China Daily Information Co (CDIC). Without written authorization from CDIC, such content shall not be republished or used in any form. Note: Browsers with 1024*768 or higher resolution are suggested for this site.
License for publishing multimedia online 0108263

Registration Number: 130349