What is Arrokoth known for in the context of space exploration?

Arrokoth, formerly known as 2014 MU69, is significant in the context of space exploration primarily because it is a contact binary visited by the New Horizons spacecraft in January 2019. A contact binary consists of two bodies that are gravitationally bound and touch each other, which is a fascinating feature indicative of the early solar system's building blocks. The New Horizons mission provided valuable data about Arrokoth, giving scientists insights into its surface composition, geology, and the formation history of small bodies in the Kuiper Belt. This visit marked an important milestone in our understanding of the outer solar system and the characteristics of primordial objects.

The other options refer to different topics in space exploration. The first exoplanet discovered pertains to planets outside our solar system, while the largest asteroid in the belt points to specific objects in the asteroid belt, and a potential dwarf planet relates to classifications that do not describe Arrokoth accurately. Thus, the focus on Arrokoth as a contact binary underscores its unique significance in enhancing our knowledge of cosmic formation.