Once upon a time, a spaceship made a dramatic quest to a distant land to bring back treasure – and some science.
And this spaceship, Japan Hayabusa2 mission, sticks to the fairytale theme for its naming conventions on the asteroid Ryugu. The name of the asteroid, that of its single giant boulder, and that of the mission’s landing site all take their names from a well-known story, as do several other sites on Ryugu. Other characteristics of space rock come from children’s stories.
Hayabusa2 arrived at Ryugu on June 27, 2018. Since then he has spent time studying the asteroid, dropping a lander and two small robotic rovers on its surface. He also fired an explosive into the surface that allowed the spacecraft to collect samples that will be transported to Earth when Hayabusa2 turns home, in December 2020.
Related: Watch below! Japan’s Hayabusa2 drops target markers on asteroid Ryugu
Right now, the asteroid is “as mysterious as a fairy tale,” Ryugu lead researcher Seiji Sugita of the University of Tokyo told Space.com. After Hayabusa2 finishes his observations and bring home pieces of the asteroid, maybe part of this mystery will become clearer.
The tale itself
The asteroid itself takes its name from Japanese folklore, in which Ryūgū-jō is the name of a dragon palace under the sea. Its most famous appearance comes from the story of Taro Urashima, whom Sugita called ” a very sappy Japanese fairy tale “.
Urashima is a kind fisherman who saved a sea turtle of a group of children who mistreated him. The sea turtle returns to Urashima a few days later and invites him to join her at Ryugu, a castle under the sea. The fisherman accepts the invitation and travels under the ocean with the turtle.
“He had a great time in the Palace at the Bottom of the Sea for three days,” Sugita said. While visiting the palace, Urashima met a princess, Otohime, who lived in the palace with her father, Ryujin. Unbeknownst to her, the princess was another incarnation of the sea turtle, and she fell in love with him during his visit.
But Urashima didn’t want this visit to last. “He wanted to go back to his village,” Sugita said. Otohime tried in vain to persuade him to stay, but he was adamant. As a farewell gift, Otohime gave Urashima a tamatebako, or treasure box, but warned him never to open it.
“I’m sure she knew he was going to open it,” Sugita said.
When Urishima returns to his village, he finds that 300 years have passed, rather than the three days he lived. “It’s like a general relativity fairy tale, ”Sugita said. Some scientists call the Urishima effect the time dilation that would occur during travel at the speed of light, he said.
The distraught fisherman took out his treasure chest and opened it. Suddenly a cloud appeared and Urishima aged rapidly.
According to Sugita, the Hayabasa2 team jokes that the same will happen to them when they finally get the sample return container by Ryugu. “When we open the capsule, our hair all turns gray!” he laughs.
Fairy Tale Names
Several of the asteroid’s features take their name from the fairy tale. Ryugu’s largest crater is called Urashima, and the massive boulder, the largest on the asteroid, is known as Otohime.
When the Hayabusa2 team was initially selecting the names, a problem arose: Otohime had already been used on Venus. The use of the princess’s name as a feature on Ryugu was initially rejected by the International Astronomical Union (IAU), the organization responsible for the official names of objects in the solar system.
“But Otohime is an extremely important person in the history of Taro Urashima,” wrote Rina Noguchi and Yuri Shimaki, both scientists at the Japan Aerospace Exploration Agency, which is leading the mission. Hayabusa2 website. “How can we get the tamatebako back if Otohime isn’t on Ryugu?”
Because the name was important to the project, the Hayabusa2 team refined their proposal to the IAU, which ultimately accepted it.
Ryugu’s shape resembles a spinning top, which the Hayabusa2 team members said looked like a dragon or ouroboros – a dragon or snake swallowing its own tail – curling around the asteroid. Because of this inspiration, the team named the crest for Ryujin, the ruler of the Dragon Palace and father of Otohime.
Hayabusa2 continues to reveal details about this fairytale world, and the samples it has collected will return to Earth at the end of 2021. We can only hope that the scientists on the mission do not age significantly once they do. they will have their own treasure chest in hand!