Where is the “End of the Earth”?

On the edge of the distant, cold, darkness of the solar system—over the rocky planets, beyond the giant air masses, a 1.6 billion-kilometer-long distance from Pluto—floating a mysterious miniature world of ice.

Astronomers named it “The End of the Earth.” This is an old cartographic term that means “beyond the known world”. It is in the Kuiper Belt, the third zone of the solar system that has not yet been explored, about 6.5 billion kilometers from the Sun, with millions of cold, small stars.

Although there are many small stars in the Kuiper Belt, no star has ever been observed at such a close distance. The two “Traveler” detectors in the United States crossed the “Third Zone” decades ago – if they were equipped with the right instruments, they might have a chance to spy on one of them. However, at the time, the “Keipub Belt” had not been discovered.

On New Year’s Eve in 2019, NASA’s detectors met for the first time with one of the mysterious space rocks.

At 9:33 pm PST, the “New Horizons” detector flew over the “End of the Earth”. This is the first time that a human spacecraft has visited such a distant place – 1.6 billion kilometers outside Pluto.

Astronomers almost never know what is waiting for them. “What does it look like? No one knows. What constitutes it? No one knows. Does it have a ring? Is there a satellite? Is there an atmosphere? No one knows. But soon, we will open that Gifts, look at what’s in the box and find out the answer,” said Alan Stern, the principal investigator of the mission.

The “New Horizons” detector has been in travel for 13 years and has flown more than 6 billion kilometers before it has arrived. It looks good now. Mission planners earlier confirmed that after determining that large objects (such as satellites) and smaller objects (such as dust) were unlikely to pose a threat to spacecraft, they decided to let the “New Horizons” be 3,500 kilometers away from the “End of the Earth”. Flying over, the speed exceeds 4,900 kilometers per hour.

“When you fly fast, you are hit by something that is the size of a grain of rice, and it can damage the spacecraft,” said project scientist Harvard Weaver.

The distance between “New Horizons” and “End of the Earth” is nearly three times that of Pluto in the summer of 2015. The photos taken at the time of the “New Horizons” are the most detailed photos to date, including not only the photos of the “pre-planet” but also the photos of the outer solar system.

“The End of the Earth” looks like a reddish “snowman”, and Chinese netizens call it “cucurbit baby.”

Based on the distance between the “New Horizons” and the “End of the Earth”, the images it collects are more detailed, and the “records” that go into space have increased by 1.6 billion kilometers. “Pluto lets us open a door,” Stern said. “But now we are looking for something more primitive.”

“Gourd baby”
In 2014, Stern and his team used the Hubble Space Telescope to find a place where the New Horizons could go after a short encounter with Pluto, and then discovered the End of the Earth. At that time, it did not have this friendly name. In the official file, it was called “2014 MU69”.

In the first batch of pictures returned, “End of the Earth” is just a pixel. In the latest image taken by the New Vision’s long-range reconnaissance imager, the star still looks like a brighter spot in the spotted ocean.

Planet scientist Amanda Zangari said: “When you look for it, it seems to have traces everywhere.” For most of December 2018, she collected the position and brightness measurements of the “End of the Earth”. .

“In order to see it, you need to overlay multiple images, count the values ​​between them, and then remove the force exerted by the planet.” It is only 1/100 of the diameter of Pluto, one ten thousandth of the brightness, “End of the Earth” is A more pretentious “prey” than a planet.

“The End of the Earth” looks like a reddish “snowman”, and Chinese netizens call it “cucurbit baby.”

Regardless of the “nickname”, the dumbbell-shaped “End of the Earth” has a total length of 31 kilometers, the large sphere is called “Tianya”, and the small sphere is called “Cape”.

Archaeological exploration
“The End of the Earth” may be very, very old. This is why astronomers are excited to study it at close range.

The Kuiper Belt celestial bodies like “The End of the Earth” are considered to be the remnants of the formation of the solar system – these cosmic wastes still existed after the formation of the planet about 4.6 billion years ago. They have a “perfect” “archaeological” value, and astronomers believe that they are preserved at temperatures close to absolute zero.

NASA plans to let the detectors visit the “End of the World” or “Cape”, draw its characteristics, study its composition, detect its atmosphere (if it exists), and search its satellites and belts – not just a simple flight task. This is an archaeological expedition to study the size and development of the universe.

The New Horizons will use the same instrument suite as the Pluto system to study the End of the Earth. The three optical devices capture the color and black and white images of the object, map the terrain, and search for gases emanating from the surface. The two spectrometers will also search for charged particles around the “End of the Earth”; a radio science instrument will measure the surface temperature; the dust counter will detect spots in the interplanetary dust cloud.

Piano-sized detectors are packed full of weight and weigh just over 1,000 pounds, and the power required to operate the equipment is less than that required for a pair of 100-watt bulbs.

After the flight, the “New Horizons” will continue to move forward and leave the “Kuibo Belt”. The “third zone” is very broad. Even if it is moving at a speed of nearly 15 kilometers per second, the “New Horizons” will take 10 years to cross the “third zone” and enter the interstellar space.

Stern and his colleagues will use this time to find new targets—a goal farther away from the Sun than the End of the Earth, perhaps with a more mysterious veil. This is an attractive prospect for the team of the New Vision.

“Exploring a place you know nothing about,” Weaver said. “This is the best adventure.”