Monday , November 30 2020

Scientists are preparing spacecraft adjacent to obscure celestial bodies near Pluto



An artist's impression of NASA's New Horizon spacecraft crashing into the 2014 MU69, a Kuiper Belt object orbiting one billion miles (1.6 billion miles) beyond Pluto.

Steve Gribben / NASA / JHUAPL / SwRI / Steve Gribben

When the fastest spacecraft ever launched races against its rendezvous with the farthest ever explored, scientists are eagerly awaiting answers to a wide range of questions about an obscure celestial body called Ultima Thule, including what it can say about the origin and formation of Our solar system.

Never before has there been such a lack of space with so little prior knowledge of what to expect. Ultima Thule was first discovered in 2014 – more than eight years after NASA's new horizons, spacecraft was already launched on its mission to explore Pluto and share beyond. And not until new horizons shoot past the remote plane on Monday night, someone will have a clue about some of the object's most basic features, including its shape and rotational speed, or whether it is two different objects nearby.

"We really only have a sketch of an idea of ​​what we will find there," said JJ Kavelaars, an astronomer with Canada's National Research Council. "It makes it so exciting."

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As part of the science team for the historical meeting, Dr. Kavelaars weekend at the campus site at Johns Hopkins University's Applied Physics Laboratory in Laurel, Maryland, which serves as the headquarters of the New Horizon mission.

His presence, along with colleague Stephen Gwyn's colleague, is due to the ultra-sharp vision of the Canada-France-Hawaii telescope at Mauna Kea, which helped identify Ultima Thule as a target for New Horizons and accurately measure its position to ensure that the spacecraft can get there with a minimum of fuel used on course corrections. (The object's name is based on old maps and is a metaphor for the farthest places.)

On the other hand, Canadian scientists will be among the first to catch a fleeting glimpse of an object as old and untouched that, in essence, it is a direct example of one of the solar system's original building blocks as those who went in to create the planets over. four and a half billion years ago.

"It's going to be the coolest thing I've done so far and probably the coolest thing I will ever do," said Dr. Gwyn, whose calibration of Ultima Thule's position proved so targeted that engineers could skip one of the spacecraft's planned engine burners to adjust the headline a few years ago.

For researchers who have been with New Horizons since the beginning, the Ultima Thule is the cake city for a mission that met its main goal in spectacular fashion in the summer of 2015, when it became the first spacecraft to visit and reveal Pluto.

Among its greatest discoveries, Pluto is a complex and dynamic world with a different surface made of nitrogen and other frozen gases and evidence of continued geological activity.

But even before New Horizons had finished sending his pictures and other data from Pluto and its moons, scientists were busy gartering for the second action of the mission: a closer meeting with the Kuiper Belt.

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Named after Dutch-American astronomer Gerard Kuiper, the belt is a region of small ice bodies at the sun's shady fringes. It begins at the Neptune's orbit, the extreme of the great planets, and extends for another three billion miles. Within the vast area, astronomers estimate that there are tens of thousands of objects larger than 100 meters in size – the remaining raw material formed by the solar system.

Although defined by its location, scientists have long known that the Kuiper Belt consists of two separate populations. A population consists of ice bodies, including Pluto, which is supposed to have formed somewhat closer to the sun and then thrown into the Kuiper belt through gravity interactions with Uranus and Neptune.

Ultima Thule is another matter. With an estimated diameter of only 32 kilometers, its orbital properties suggest that it belongs to the population of objects formed within the Kuiper Belt and never left. Distant and undisturbed, it provides a window on the deep past and a rare chance of anchoring ideas of planetary formation with some solid data.

"We are desperate for restrictions in this process," said Brett Gladman, an astronomer at the University of British Columbia.

In a research paper submitted online last week, Dr. Gladman and colleagues predict how many craters New Horizons will see peeling Ultima Thule's frozen surface. This four-and-a-half-year record of effects can be treated as an interplanetary census because different-diameter craters represent the size distribution of objects within the Kuiper Belt.

An accurate crater count will be one of several ways in which New Horizons will probably tell what scientists understand about how solar systems are made when running within 3,500 km of Ultima Thule on Monday night. (The spacecraft is moving so fast in relation to its target – about 14.4 km per second – that its pictures would blur if it went closer.)

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But while the reconnaissance is fast, it will take the better part of a day for scientists to come back only one image of Ultima Thule. This is because the spacecraft is now so far away, and the signal is so weak it transmits data in step with a 1970s telephone modem. The first glimpse could be released as early as Tuesday, if the researchers are lucky with how they pointed the spacecraft and in their choice of which frames must first be downloaded. More pictures will follow the next several days.

The delayed satisfaction is a small price to pay for researchers who have spent years preparing for the meeting, including a number who are NASA employees and work without pay during a partial decommissioning of the US government. Besides Dr. Kavelaars and Dr. Gwyn includes international members of the science team Brian May, an astrophysicist better known to the world as a guitarist with the rock band Queen.

"Very few teams have had this experience and privilege to cross the entire solar system," said Alan Stern, mission's main researcher on Friday. "We've worked so hard. People are ready to see that payout and see what we can learn about the birth of our solar system."


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