In a new study, Japanese scientists say that they have figured out where asteroid Ryugu might have come from. Which asteroid could possibly be Ryugu’s parent?

Hayabusa 2

Japan’s Hayabusa 2 has been on the asteroid Ryugu since June 2018. After being on the asteroid for months, the spacecraft has gathered quite a bit of information. In fact, last September, it launched two tiny rovers to explore the asteroid’s surface, and just last February, it collected rock samples from the surface.

One of the mysteries about Ryugu, however, is exactly where it might have come from. Small asteroids such as Ryugu are believed to come from older parent rocks during the evolution of the solar system, and its orbit suggests that it came from the mini asteroid belt between Mars and Jupiter.

So far it has been difficult to pinpoint exactly where Ryugu came from, but in a study published in the journal Science, scientists believe that they might have figured out two possible asteroids that could be Ryugu’s parent.

Ryugu’s Parent

For one thing, Ryugu has quite a dark color, and in fact, it is considered to be one of the darkest objects in our solar system. As such its color best matches with two main-belt asteroids, Polana and Eulalia. According to the scientists, the chances that Ryugu came from one of those two is about 80 to 90 percent.

Furthermore, researchers were able to determine from Ryugu’s surface that its parent likely had water on its surface but lost a lot of it before the break up that led to Ryugu. However, truly understanding Ryugu’s water history and age may only come in 2020, when Hayabusa 2 returns to earth with samples from its surface.

By then, the samples might be able to help scientists determine whether Ryugu came from the older Polana or the younger Eulalia.