The distant object was discovered by the Hubble Space Telescope in 2014. The asteroid is more than six billion kilometers away. It’s a preserved relic dating all the way back to our solar system’s origin, 4.5 billion years ago. No spacecraft has visited anything so primitive before. New Horizons will fly within 3,500 kilometres of the asteroid. The final sequence of flyby instructions were sent on Christmas Day. It takes 12 hours for the messages to be transmitted to the spacecraft. In the Encounter Mode if there were to be an issue with the flyby instructions sent from Earth, the onboard software will take over and correct any problems itself, instead of calling back to Earth. NASA will take photos of Ultima, but has no idea what it will reveal.
But they think “in effect, Ultima should be a valuable window into the early stages of planet formation and what the solar system was like over 4.5 billion years ago.” The encounter is a difficult goal. The spacecraft is older, the target is smaller, the flyby is closer and the distance from us is greater. NASA launched the spacecraft in 2006, and it’s about the size of a baby grand piano. New Horizons hurtles through space at 50,700 kilometers per hour, and even something as minuscule as a grain of rice could demolish it. It will take almost two years for New Horizons to beam back all its data on Ultima Thule.