New technology has given a new perspective to an old mystery: How did life on Earth arise? Before life appeared on our planet, the atmosphere was less dense during what researchers call the prebiotic phase. This meant that high-energy radiation from space was everywhere and ionized molecules. Some suggest that small pools of water containing urea, an organic compound needed to form nucleobases, were exposed to this intense radiation, leading to the conversion of urea into reaction products. They would serve as the building blocks of life: DNA and RNA.

But to learn more about this process, scientists needed to delve deeper into the mechanism of urea ionization and reaction, as well as reaction pathways and energy distribution.

Corresponding author Zhong Yin, currently an associate professor at the International Center for Synchrotron Radiation Innovation (SRIS) at Tohoku University, and an international collaborating group consisting of colleagues from the University of Geneva (UNIGE) and ETH Zurich (ETHZ). The University of Hamburg has managed to discover more thanks to the innovative approach of X-ray spectroscopy.

Using a high-harmonic light source and a submicron flat liquid jet, the technology allowed researchers to study chemical reactions occurring in liquids with unprecedented temporal precision. More importantly, the pioneering approach allowed researchers to investigate complex changes in urea molecules at the femtosecond level, a quadrillionth of a second.

“We showed for the first time how urea molecules respond after ionization,” says Yin. “Ionizing radiation damages urea biomolecules. However, during the scattering of radiation energy, urea undergoes a dynamic process that occurs on the femtosecond time scale.”

Previous studies examining molecular reactions were limited to the gas phase. To extend this to the aquatic environment, a natural environment for biochemical processes, the group needed to develop a device that could produce an ultrathin jet of liquid less than a millionth of a meter thick in vacuum. A thicker jet may interfere with measurements by absorbing some of the X-rays used.

Yin, who serves as the lead experimenter, believes his findings provide more than an answer to how life on Earth emerged. It also opens a new path in the new scientific field of atochemistry. “Shorter pulses of light are needed to understand chemical reactions in real time and push the boundaries of atochemistry. Our approach allows scientists to observe a molecular movie, following each step of the process.” Source