London: In a first, scientists have found the presence of organic matter -- the ingredients essential for life -- in two liquid-water-containing space meteorites that separately crashed to Earth in 1998 after circulating in our solar system's asteroid belt for billions of years.
The chemical makeup within tiny blue and purple salt crystals sampled from these meteorites, known as Monahans and Zag, showed a mix of complex organic compounds such as hydrocarbons and amino acids.
"This is really the first time we have found abundant organic matter also associated with liquid water that is really crucial to the origin of life and the origin of complex organic compounds in space," said lead author Queenie Chan, a planetary scientist and postdoctoral research associate at the Open University in Britain.
The findings, published in the journal Science Advances, showed evidence for the pair's past intermingling and likely parents.
These include Ceres, a brown dwarf planet that is the largest object in the asteroid belt, and the asteroid Hebe, a major source of meteorites that fall on Earth.
One of the meteorites smashed into the ground near a children's basketball game in Texas in March 1998, while the other hit near Morocco in August 1998, suggesting that their asteroid hosts may have crossed paths and mixed materials.
The meteorite crash yielded 2-millimetre-sized salt crystals, which contain organic solids and water traces measure just a fraction of the width of a human hair.
Carefully preserved at NASA's Johnson Space Center in Texas, the crystals carried microscopic traces of water that is believed to date back to the infancy of our solar system - about 4.5 billion years ago, Chan said.