Context

NASA’s spacecraft New Horizon is hurtling towards a historic New Year's Day flyby of the most distant planetary object ever studied, a frozen relic of the early solar system called Ultima Thule.

About

New Horizon Mission

• Launched in 2006, the mission is first of its kind to study the Pluto and Kuiper Belt of the solar system.
• The New Horizons mission will help understand worlds at the edge of our solar system by making the first reconnaissance of the Pluto system and by venturing deeper into the distant, mysterious Kuiper Belt – a relic of solar system formation.

Science behind the mission

• Generally, New Horizons seeks to understand where Pluto and its moons “fit in” with the other objects in the solar system, such as the inner rocky planets (Earth, Mars, Venus and Mercury) and the outer gas giants (Jupiter, Saturn, Uranus and Neptune).
• Pluto and its largest moon, Charon, belong to a third category known as “ice dwarfs.” They have solid surfaces but, unlike the terrestrial planets, a significant portion of their mass is icy material.
• Using Hubble Space Telescope images, New Horizons team members have discovered four previously unknown moons of Pluto: Nix, Hydra, Styx and Kerberos.
• A close-up look at these worlds from a spacecraft promises to tell an incredible story about the origins and outskirts of our solar system. New Horizons also will explore – for the first time – how ice dwarf planets like Pluto and Kuiper Belt bodies have evolved over time.
  
  

  Ultima Thule  It is a relic of early solar system, the most distant planetary object ever studied. This is the most primitive object ever encountered by the spacecraft in the solar system. It lies in the Kuiper Belt which is a freezing area of the solar system.  Kuiper Belt  It is a vast cosmic disc left over from the days when planets first formed. Astronomers sometimes call it the "attic" of the solar system. Scientists didn't even know the Kuiper Belt existed until the 1990s. The Kuiper Belt begins some 4.8 billion kilometers beyond the Sun, past the orbit of Neptune which is the furthest planet from the Sun. It is teeming with literally billions of comets, millions of objects like Ultima which are called planetesimals  Planetesimals They are the building blocks out of which planets were formed. These are now found in the Kuiper Belt of the solar system.