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Scientists are preparing to meet a spacecraft with an unknown celestial body near Pluto



The artist’s impression of the New Horizons NASA spacecraft meeting 2014 MU69, an object of the Kuiper belt, which rotates one billion miles (1.6 billion kilometers) from Pluto.

Steve Gribben / NASA / JHUAPL / SwRI / Steve Gribben

As the fastest spacecraft ever launched, it raced to its rendezvous with the furthest explored site ever, scientists are eagerly awaiting answers to many questions about an obscure celestial body named Ultima Thule, including what he can say about the origin and formation of our solar system. ,

Never before has such a space meeting played so little prior knowledge of what to expect. Ultima Thule was discovered only in 2014 – more than eight years after the launch of the NASA spacecraft "New Horizons" in order to study Pluto and its parts. And only until New Horizons shoots past a remote planetoid on Monday night, no one can understand some of the basic characteristics of an object, including its shape and speed of rotation, or these are two separate objects in close proximity.

“We actually have only a sketch of the idea of ​​what we will find there,” said J.J. Cavelaars, astronomer of the National Research Council of Canada. "That's what makes it so exciting."

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As part of a research team on the historic meeting, Dr. Kavelaars spent the weekend at the camp at the Applied Physics Laboratory at Johns Hopkins University in Laurel, Maryland, which serves as the headquarters for the New Horizons mission.

His presence there, along with NRC colleague Stephen Gwyn, is explained by the super-acute vision of the Canada-France-Hawaii telescope on Mauna Kea, which helped identify Ultim Thule as a target for New Horizons and accurately enough measured his position the ship could get there with a minimum amount of fuel spent on course correction. (The name of the object is based on ancient maps and is a metaphor for the most remote places.)

In turn, Canadian researchers will be among the first to catch a fleeting glimpse of an object so ancient and untouched that it is, in fact, a direct example of one of the original building blocks of the solar system, such as those that were created to create planets throughout four and half a billion years ago.

“This will be the coolest thing I have ever done, and perhaps the coolest thing I was ever going to do,” said Dr. Gwin, whose position calibrations for Ultima Thule were so targeted that engineers could skip one of them. from a scheduled spacecraft engine burns to adjust the course a couple of years ago.

For scientists who have been with New Horizons since the very beginning, the overflight of the Ultima Thule is the icing on the cake for the mission, which effectively fulfilled its main task in the summer of 2015, when it became the first spacecraft to visit and show Pluto.

Among his major discoveries was that Pluto is a complex and dynamic world with a diverse surface consisting of nitrogen and other frozen gases, and evidence of the continuation of geological activity.

But even before the New Horizons finished transmitting their images and other data from Pluto and its satellites, the scientists were busy preparing for the second act of the mission: closer acquaintance with the Kuiper belt.

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Named after the Dutch-American astronomer Gerard Kuiper, the belt is a region of small ice bodies on the dark edges of the solar system. It begins in the orbit of Neptune, the outermost of the major planets, and extends another three billion kilometers. According to astronomers, tens of thousands of objects more than 100 meters in size are located on this vast territory – the remaining raw materials from which the Solar System was formed.

While this is determined by its location, scientists have long known that the Kuiper Belt consists of two separate populations. One population consists of ice bodies, including Pluto, which are believed to have formed somewhat closer to the Sun, and then were thrown into the Kuiper Belt through gravitational interactions with Uranus and Neptune.

Ultima Thule is another matter. The estimated diameter of the orbit is only 32 kilometers, and it refers to the totality of objects that were formed in the Kuiper belt and never left it. Distant and undisturbed, it offers a window into the deep past and a rare opportunity to consolidate ideas about the formation of planets with some reliable data.

“We desperately need to limit this process,” said Brett Gladman, an astronomer at the University of British Columbia.

In a research article published last week on the network, Dr. Gladman and his colleagues predict how many New Horizons craters will see on the frozen surface of Ultima Thule. This four-and-a-half-billion-year collision report can be viewed as an interplanetary census, because the craters of different diameters represent the size distribution of objects within the Kuiper belt.

The exact number of craters will be one of several ways that New Horizons will likely tell you that scientists understand how solar systems are created when they go around 3,500 km from Ultima Thule on Monday evening. (The spacecraft is now moving so fast relative to its target – about 14.4 kilometers per second – that its images will be blurred if you get closer).

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But while intelligence is fast, scientists need the best part of the day to return only one image of Ultima Thule. This is due to the fact that the spacecraft is now so far away and its signal is so weak that it transmits data at the speed of a telephone modem from the 1970s. This first glimpse can be released as early as Tuesday, if scientists are lucky in how they pointed out the spacecraft, and in choosing which frames to load first. Over the next few days other images will appear.

This deferred remuneration is a small price for scientists who have spent years preparing for this meeting, including a number of NASA employees who work without a salary during the partial closure of the US government. In addition to Dr. Kavelaars and Dr. Gwin, an international team of scientists includes Brian May, an astrophysicist who is better known in the world as guitarist for the rock band Queen.

“Very few teams had this experience and this privilege to cross the entire solar system,” said Alan Stern, the mission’s chief investigator on Friday. “We worked so hard. People are ready to see this reward and see what we can learn about the birth of our solar system. ”


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