Researchers who have analyzed samples from the Ryugu asteroid say its parent body is believed to have had large amounts of water.

The samples were collected and brought back to Earth by Japan's Hayabusa2 space probe in 2020.

Eight teams in Japan have been analyzing the materials. The first detailed data have been released by two of them.

A team says 23 different amino acids, including glutamic acid and aspartic acid, have been found in the samples.

Both of the teams say they found large amounts of minerals that formed through chemical reactions involving liquid water.

They say this suggests that the parent body of Ryugu had large amounts of water, and this was gradually lost as it broke up through collisions before the asteroid was formed.

The team led by Okayama University says the chemical reactions involving water were found to have peaked 2.6 million years after the formation of the solar system. It estimates the temperature of the water at between zero and 30 degrees Celsius.

The other team, led by the Japan Aerospace Exploration Agency, says the body is believed to have had water with a temperature of around 40 degrees roughly 5 million years after the formation of the solar system.

The data provided by both of the teams are expected to provide important clues about the early stages of the solar system.