New Horizons Visits Farthest Object: Arrokoth

On January 1, 2019, NASA's New Horizons space probe achieved a historic milestone by flying past Arrokoth, a distant object in the Kuiper Belt. This event marked the farthest object from the Sun ever visited by a spacecraft, providing invaluable insights into the early Solar System.

The New Horizons Mission

Launched by NASA in 2006, the New Horizons spacecraft was designed to explore the outer reaches of our solar system. Its primary mission was to study Pluto and its moons. However, it also had a secondary objective: to visit and study other objects in the Kuiper Belt.

The Johns Hopkins University Applied Physics Laboratory and the Southwest Research Institute engineered the probe. After its successful Pluto flyby in 2015, New Horizons continued its journey, setting its sights on a new target.

Discovering Arrokoth

Arrokoth, provisionally designated 2014 MU69 and formerly nicknamed Ultima Thule, is a trans-Neptunian object. These are celestial bodies that orbit the Sun at a greater average distance than Neptune. Arrokoth resides in the Kuiper Belt, a region populated by icy bodies beyond the orbit of Neptune.

This object became the focus of New Horizons' extended mission. Its distant location and primitive nature made it an ideal candidate for understanding the conditions of the early Solar System.

A Glimpse into the Past

The flyby on January 1, 2019, allowed scientists to observe Arrokoth up close. The probe revealed that Arrokoth is a contact binary, meaning it is composed of two distinct planetesimals joined together. These two lobes measure approximately 21 km and 15 km across.

Arrokoth's characteristics, including its composition and shape, offer clues about how planets and other bodies formed in the early Solar System. Its classification as a cold classical Kuiper Belt object suggests it has remained largely unchanged since its formation billions of years ago.

Key facts

• NASA's New Horizons spacecraft flew by Arrokoth on January 1, 2019.
• Arrokoth is a trans-Neptunian object located in the Kuiper Belt.
• This flyby made Arrokoth the farthest object from the Sun ever visited by a spacecraft.
• Arrokoth is a contact binary, composed of two planetesimals joined together.
• New Horizons was launched by NASA in 2006.

Frequently asked questions

What is a trans-Neptunian object?

A trans-Neptunian object (TNO) is any minor planet in our Solar System that orbits the Sun at an average distance greater than Neptune. Arrokoth is an example of a TNO found in the Kuiper Belt.

Why was the Arrokoth flyby significant?

The flyby was significant because Arrokoth became the most distant and primitive object visited by a spacecraft. Studying Arrokoth helps scientists understand the formation and early conditions of the Solar System.