Mystery surrounding the origin of life has fascinated scientists and prompted NASA to conduct a new study involving meteorites, which may finally reveal the secret. The recent study on meteorites opens the discussion for a new hypothesis on how life was formed on Earth. The results of the study revealed DNA from meteor dust that could dispel theories based on how life originated over three million years ago. Common theories involve an electronic spark, molecules in the sea, ice, cell membranes and the idea that life actually originated on Mars.
Michael Callahan and his team at NASA have found evidence from meteorites that suggest the secret of the origin of life lies in the DNA and proteins they showered on Earth. DNA, of course, is the blueprint for living things. The team at Goddard’s Astrobiology Space Center used new technology that revealed amino acids in the carbon-rich meteorites.
These meteorites, known as carbonaceous chondrites, contain the same amino acids that make up protein. They are the building blocks of life and are responsible for creating DNA, skin, and hair. Their discovery points out how meteor impacts can provide answers for how life originated on Earth. They contain low amounts of molecules that scientists believe are life-forming. The dust particles steadily supplied organic material to the Earth.
They also discovered molecules and organic compounds, including nitrogen heterocycles. Other biological similarities link the meteorites and metabolism, as it is known today.
The NASA scientists used a liquid chromatography instrument to study the dust particles 1,000 times smaller than their actual size. “Our study was proof-of-concept,” said Callahan, lead author of the research published in the Journal of Chromatography A.
The device allowed them to take a closer look than ever before. The molecules received an electric charge by a nanoelectrospray emitter, then the machine moved them to an inlet of the mass spectrometer, which gave the team the ability to see specific molecules in the sample of meteorite dust.
Getting the initial readings provided a challenge, according to Callahan. Studying the samples has been difficult in the past due to their incredibly small size. He credits the sensitivity of the machine they used for the results they were able to produce. Studying the biological relevance of meteorites is new territory and needs further exploration. He plans on using the same technology to study other planetary materials in the future.
The concept is of meteorite particles being responsible for the origin of live of Earth is being met with criticism, however, because these carbon-rich meteorites are rare and make up only five percent of the ones that have been studied. The new discovery is not well received by skeptics since these particles are among many that have fallen to Earth. Callahan argues that though they are small, their impact is due to a high quantity of extraterrestrial matter. Their biological relevance and connection to life formation needs more research, but the newest technology shows that the protein found in the meteorites may have revealed the secret to the origin of life.
By Tracy Rose