"Like a fly in amber:" two meteorites with ingredients for life

Saturday, 13 Jan, 2018

Two headstrong space rocks, that independently wrecked into earth in 1998, after transmitting in our solar system's asteroid belt for eons, have something else to share; the components of life.

"While the rich deposits of organic remnants recovered from the meteorites don't provide any proof of life outside of Earth, the meteorites' encapsulation of rich chemistry is analogous to the preservation of prehistoric insects in solidified sap droplets".

However, if life did exist in some form in the early solar system, these meteorites would have trapped life or biomolecules with their salt crystals that carried microscopic traces of water that might have existed when the solar system was still young - about 4.5 billion years ago.

An global team, including scientists from the Open University (OU) in the United Kingdom and Nasa Johnson Space Centre in Texas, found amino acids - which form the basis of proteins, hydrocarbons - organic compounds made up of hydrogen and carbon, and liquid water - the most important ingredient required to support life, within the salt crystals.

It took scientists nearly two decades to comprehensively analyze samples from the pair of meteorites that were believed to have existed some 4.5 billion years ago.

When the two rocks fell to Earth, one in Texas and the other a few months later in Morocco, they were preserved by Nasa for further studies.

But how did the complex suite of organic compounds landed on the space rocks? The crystals were around two millimeters in size and contained organic solids and water traces a mere fraction of the width of human hair.

The required technology was not yet available at the time when the meteors were discovered.

The in-depth analysis of the millimeter-sized salt crystals from the meteorites took time to complete because scientists needed a highly-sensitive instrument to study the crystals of amino acids at nanoscopic scales.

It's worth noting that the research that was undertaken in order to produce these findings took place in NASA's Johnson Space Center, in what is widely believed to be the cleanest laboratory in the world, thanks to the need to ensure that Earth microbes don't infect scientific experiments that are sent out into space. The scientists suspected that the crystals might have originally been seeded by ice- or water-spewing volcanic activity on Ceres.

Scientists believe that this discovery leads to the conclusion that the origin of life is possible elsewhere.

"The asteroidal parent body, potentially asteroid 1 Ceres, shows evidence for a complex combination of biologically and prebiologically relevant molecules", says the study published in Science Advances. "There is a great range of organic compounds within these meteorites, including a very primitive type of organics that likely represent the early solar system's organic composition".