Japan's science ministry says more than 20 types of amino acid have been found in samples collected from the Ryugu asteroid. The discovery may help scientists better understand the origins of life, as amino acids are one of its basic building blocks.

The sand and dust samples were collected from the asteroid and brought to Earth by Japan's Hayabusa2 space probe in 2020.

Eight teams in the country, including one at the Japan Aerospace Exploration Agency, have been analyzing the materials.

Amino acids are an essential substance in most forms of life and are thought to have existed since shortly after the Earth was formed.

One theory suggests that they ceased to exist on Earth during a period when the planet became extremely hot but were reintroduced from outer space by meteors.

The ministry says the eight teams are wrapping up their analyses, and detailed data are expected to be made public in academic papers and other publications.