What is Ultima Thule? In the works of ancient Greek and Roman history and geography, the northernmost Scandinavian countries are so named. In later times the meaning of the term became slightly less related to the north and meant that just outside the area of the known world. But the connection with Scandinavia, at least in the Scandinavian spirit, has certainly survived – not just the music group of Sweden, Estonia and other neighboring countries.
What is it to fly to Norway? The Ultima Thule, to which New Horizons flies, does not have many oil, black metal and herring factories. The official name of this facility is MU69 2014 – which means that it was discovered in the second half of June (only one year before the visit of the New Horizons to the Pluto district) in the second half of June (the first letter indicates half of the month when the object was detected) and during that half month it was 1745 found object (number 69 * 25 + 20 – You are the alphabetical letter used for naming 20). Every year there are tens of thousands of small objects in the solar system, so it is both impossible and impractical to give them all the names they need to meet the code numbers.
What is 2014 MU69? This is the purpose of the Kuiper ring – one of the millions of asteroids, comets and similar bodies that run around the edge of the solar system, on a very neat disk behind the orbit of Neptune. The borders of the Kuiper ring are usually referred to as 30-50 astronomical units of the sun; The radius of the orbit of Neptune is 30 astronomical units. Pluto, Haumei and Makemak are the three largest known Kuiper ring objects – the dwarf planet. Ultima Thule has an average of 44.5 astronomical units away from the sun, and one wheel around the star has been running for more than 300 Earth years. We know very little about it so far: it seems that it consists of two parts, perhaps as a comet 67P / Churiumov-Gerasimenko examined by Rosetta, perhaps only a binary object whose members rotate very close together. Parts are similar in size, 18 and 20 km in diameter. The fact that the shape of the object is so unusual, we learned later than New Horizons was focused on – only in mid 2017. New Horizons coming this evening will improve this knowledge many times.
Why is New Horizons flying there? In July 2015 the probe flew through Pluto and flew away – to prevent him from entering the orbit around this dwarf planet, no chance. The 16-month transfer of collected data to Earth could have been the end of the mission, but astronomers thought that the probe could be used for at least one other study. The Kuiper ring objects are somewhat like asteroids, but they differ greatly from the objects. One of the biggest differences is that the asteroids are usually rocky or metallic, while the ice-cold bodies fly into the Kuiper ring. Sometimes one or the other comes close to the sun, but we see them as comets. Comets that are exposed to sunlight evaporate, so we see objects that are far away from the star and are not affected. So a flight through a small object of the Kuiper ring gives you the opportunity to see the original components of the solar system, from which planets may have formed.
How was this target selected? Searches started when New Horizons slept on their way to Pluto. In 2014, the observations of the Hubble telescope just went looking for a new target. Opportunities to fly to the next target were limited by the New Horizons fuel supply – it could only make a few course corrections. So, calculating where the probe could fly, that part of the air was searched and three possible targets were discovered. In October 2015, a new part of the New Horizons mission was officially launched for a visit to the MU69 environment of 2014.
How did the flight go? Four minor changes were made to the course at the end of October 2015 and the beginning of November 2015. Each time the speed of the New Horizons movement changed a few meters per second, but it was sufficient to deviate precisely to Ultima Thule. Then the probe fell asleep – switched to energy-saving mode – and slept until early June last year. After he woke up, he checked the systems when they saw they were working and started looking at the target. In mid-August he captured the target and officially started the "approach phase" of the flight. There was a current tonight, and then the probe sank to the interstellar space.
Data transfer. Like Pluto's viaduct, New Horizons collects a lot of data from Ultima Thule. The first to reach the earth within a few hours, and the transfer of all data should begin on January 9. A low transmission speed means that it will take a long time to wait – all data will reach us by the end of 2020.
The Ultima Thule flight can reveal a lot of new knowledge, not only about this specific object, but also about the qualities of the bodies that make up the Kuiper ring. Their chemical composition and physical properties, appearance, surface structure and temperature, the presence or absence of atmosphere and satellites – so far we do not know anything about these parameters.
We will know this after New Horizons flight. At the moment no similar missions are planned, so for at least a few decades it is best known to us from the edges of the solar system, from which we will try to understand how and how the solar system was formed.