‘Probably hazardous’ asteroid Ryugu as soon as had ‘flowing water’ inside it, shocking examine claims

Scientists in Japan now consider that liquid water as soon as flowed by way of the guts of the near-Earth asteroid Ryugu, after researchers detected one thing uncommon within the samples of the house rock that had been returned to our planet 5 years in the past.

The shocking findings even have potential implications for the way Earth acquired its personal water, the researchers say.

162173 Ryugu is a roughly 3,000-foot-wide (900 meter) asteroid that orbits the sun every 474 days on a trajectory that frequently overlaps with Earth’s. It is unlikely to ever hit our planet, but it is still large enough and comes close enough to us to be considered “potentially hazardous” by NASA.

Ryugu was visited by Japan’s Hayabusa2 mission between 2018 and 2019, which deployed a probe that landed on the spinning top-shape space rock and collected samples that were later returned to Earth in December 2020.

In a new study, published Sept. 10 in the journal Nature, researchers unearthed chemical irregularities within these samples, which they say can currently be explained only by the historic presence of flowing water within the asteroid.

“We found that Ryugu preserved a pristine record of water activity,” study lead author Tsuyoshi Iizuka, a geochemist on the University of Tokyo in Japan, mentioned in a statement. There can be “evidence that fluids moved through its rocks,” he added. “It was a genuine surprise!”

Related: Key constructing block for all times found on distant asteroid Ryugu — and it might clarify how life on Earth started

The new findings emerged after the crew analyzed the radioactive isotopes — uncommon variations of parts with an altered atomic mass — of lutetium (Lu) and hafnium (Hf) throughout the samples.

Lu-176 naturally decays into Hf-176 through beta decay, during which a component spits out charged subatomic particles, comparable to electrons or positrons, reworking them into one thing else. By figuring out the ratio of Lu-176 to Hf-176 and evaluating it to the half lifetime of Lu-176 — the time taken for half a pattern of the isotope to naturally decay — the crew aimed to work out how previous the samples had been.

But after they carried out their evaluation, the researchers discovered that there was far an excessive amount of Hf-176 within the samples. The researchers argue that the one factor that would correctly clarify this end result was that historic liquid water had washed away a majority of Lu-176 throughout the samples, which might have began occurring shortly after Ryugu was born.

A watery previous

“The most likely trigger [for the water] was an impact on a larger asteroid parent of Ryugu, which fractured the rock and melted buried ice, allowing liquid water to percolate through the body,” Izuka mentioned.

Recent evaluation from the James Webb Space Telescope (JWST) had suggested that Ryugu’s parent asteroid may have also spawned the asteroid Bennu, which was visited by NASA’s OSIRIS-REx mission that later returned samples of the asteroid to Earth in September 2023. However, similar signs of flowing water have not been seen within Bennu’s samples so far, creating uncertainty about the asteroids’ respective origins.

Given that Ryugu likely had flowing water, the researchers also believe that its parent asteroid may have contained ice for at least a billion years after the solar system was formed, which is far longer than most asteroids were thought to be able to hold onto their water.

“This changes how we think about the long-term fate of water in asteroids,” Izuka said. “The water hung around for a long time and was not exhausted so quickly as thought.”

It is widely accepted that a majority of Earth’s water likely came from impacts with asteroids, comets or other planetesimals in the early days of the solar system. The new findings hint that asteroids could have played a much larger role in this process than previously thought, potentially delivering up to three times more water to our planet than expected, the researchers claim.

The study team is now planning to analyze veins of phosphate within the samples, which could pin down a more accurate age for the water that flowed through Ryugu, and look more closely at the isotopes from asteroid Bennu to see if it too has signs of flowing water, according to Live Science’s sister site Space.com.