Scientists have long wondered whether water once existed beyond Earth.
Now, a major discovery has brought them closer to answering that question.
Japanese researchers have found salt minerals on the surface of the asteroid Ryugu, suggesting that liquid water was once present, reports WP.
This finding could change our understanding of how planets and moons formed in our solar system.
During the Hayabusa2 mission, scientists collected samples from Ryugu and brought them back to Earth in December 2020.
These samples contained sodium carbonate, halite (rock salt), and sodium sulfites. The results of the analysis were only recently published.
Researchers took their time to avoid contaminating the samples with Earth's atmosphere, which could alter the findings.
Toru Matsumoto, the lead scientist on the study, emphasized the importance of handling the samples carefully.
He explained that the salt crystals provided a rare look into Ryugu’s chemical past. Unlike most asteroids, Ryugu contains minerals that dissolve easily in water. T
his suggests that it might have once been part of a much larger celestial body.
Tests in the lab confirmed the presence of salt crystals. This indicates that liquid water existed at some point in Ryugu’s history.
However, the asteroid itself is not expected to contain water today. Scientists believe it may have once been part of a planetesimal—a small planetary embryo that formed early in the solar system’s history.
These planetesimals often collided and broke apart about 4.5 billion years ago.
During the chaotic formation of the solar system, radioactive isotopes could have played a role.
Their decay would have generated heat, potentially allowing liquid water to exist on Ryugu.
This process might also have led to the formation of salt crystals on other celestial bodies.
Ryugu is thought to be a remnant of a planet that existed billions of years ago.
Scientists speculate that radioactive substances within the planet could have heated it enough for water to exist at nearly 100 degrees Celsius.
When the planet broke apart, Ryugu formed. Over time, any remaining water either evaporated into space or froze.
Matsumoto stated that the salt minerals discovered are crystallized evidence of this ancient liquid.
The presence of sodium salts in Ryugu’s samples also provides valuable information about the role of water in planetary formation.
Scientists believe this discovery could be key to studying the icy moons of Jupiter and Saturn.
Understanding how water existed on Ryugu may help researchers uncover more about how these distant moons evolved.
This breakthrough could open new doors in space exploration.
