(CN) — A new study reveals the up-close and personal look astronomers got into the mysterious structure of a nearby asteroid that routinely orbits near Earth after a Japanese spacecraft managed to land on its rocky surface.
Of the seemingly countless things astrophysicists and astronomers have sought to study in the reaches of space, asteroids have long been a cosmic item of scientific interest. Scientists cite these relatively small and jagged objects as potential treasure troves of information about the mineral composition of the asteroids themselves as well as the evolution of the solar system.
One asteroid that has recently captured the attention of researchers is the object known as 162173 Ryugu, an asteroid that orbits between Earth and Mars. Ryugu, roughly half a mile wide and named after a mystical undersea palace in Japanese folklore, has earned the interest of scientists in recent years due in part to how close Ryugu is to Earth — just around 60,000 miles away at its closest orbital point.
Attempts to better understand the nearby asteroid led Japanese researchers to launch the spacecraft Hayabusa2 toward Ryugu nearly six years ago. After an almost four-year journey through space, the craft finally reached Ryugu in the summer of 2018.
Once it arrived, Hayabusa2 studied Ryugu and even touched down on the asteroid’s surface to collect some crucial rock samples. While Hayabusa2 is still making its way back to Earth after the completion of its mission and is not due to arrive with its samples until this coming December, scientists have already learned much from the experiment.
A study, released Thursday in the journal Science, reveals researchers have been hard at work studying intensely detailed pictures and videos of the asteroid Hayabusa2 has already sent back to Earth. These images, researchers say, help to clarify not just the compound structure of the asteroid, but also where it has previously traveled in our solar system.
One of the first and most immediate observations made by scientists in examining the new pictures and videos is that the asteroid seems to possess two entirely different types of surface materials. The first appears to be a redder type of substance, found typically at the mid-latitude areas of Ryugu. The other appears to a blue material that is spread largely across the asteroid’s polar regions.
Scientists don’t know why the two types of surfaces exist on a body that is not even a mile wide.
The overall surface of the asteroid, however, may tell a larger picture.
Tomokatsu Morota, first author of the study at the Department of Earth and Planetary Science at the University of Tokyo, and a group of colleagues noticed something peculiar in the high-resolution images captured by Hayabusa2 during its brief landing on the asteroid’s surface. As the craft touched down at its designated landing zone, an area of Ryugu dubbed L08-E1, researchers noticed the craft’s thrusters seemed to reveal a strange coating on the asteroid’s surface. As the thrusters continued to fire, the energy disturbed a fine and dark mineral material that thinly dusted the surrounding areas.
Researchers noticed upon closer inspection that this dust-like material seemed to share a connection with the reddish material covering the asteroid’s middle regions. This strange correspondence with the reddish materials led researchers to theorize that the presence of these minerals could be explained by Ryugu’s previous orbital history.
Researchers suggest that these minerals, coupled with the structure of Ryugu’s crater pockets, were potentially caused by an intense but brief period of solar heating at some point in its history. The powerful solar energy resulted in a permanent reddening of certain sections of the surface that are still noticeable today.
Astronomers theorize the cause for this massive solar scar stems from a past alteration of Ryugu’s orbit that took it dangerously close to the sun — a journey that left Ryugu’s surface accented with reddish minerals.
Scientists will have more information at their disposal to help answer these questions and more when Hayabusa2 returns to Earth’s atmosphere and releases a capsule, set to land in the Australian outback, filled with precious samples from the asteroid. The event will mark only the second time a successful retrieval mission from an asteroid has ever been carried out.