A sprinkling of cosmic dust may have helped kick-start life on Earth

Cosmic dust may have helped kick-start life on Earth. New findings challenge a widely held assumption that this wasn't a plausible explanation.

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The origin of life on Earth has long remained a mystery. Many theories suggest that life emerged from prebiotic chemistry, in which organic compounds formed and repeatedly self-organised until life as we know it developed. However, scientists have noted that the rocks that make up Earth's surface are relatively deficient in reactive and soluble forms of the essential elements needed for this prebiotic process, such as phosphorus, sulphur, nitrogen and carbon. In fact, life on Earth is engaged in "fierce competition" for the limited reservoirs of these elements, scientists wrote in a paper published in the journal Nature Astronomy earlier this year. So how could life have evolved under such conditions? The prevailing theory is that the ingredients necessary for life might have been delivered to Earth.