Science Focus
original post »
Over the past 40 years, evidence has turned up on Mars pointing to the presence of oxygen. This suggested that some oxygen must have been created in the early Earth’s atmosphere as well, due to the similar compositions of the two atmospheres. Before this new idea, it was widely understood that oxygen in the Earth’s atmosphere originated in an event called the “Great Oxidation Event,” which occurred about 2.4 billion years ago as the first plants appeared and converted carbon dioxide to oxygen.
But a new experiment has confirmed that there is a mechanism for creating oxygen that doesn't require the presence of life. The results have implications not only for understanding the evolution of Earth’s atmosphere, but also for the study of exoplanetary atmospheres.
The experiment
The team used a vacuum ultraviolet (VUV) laser to break carbon dioxide apart, leaving free carbon and oxygen. Vacuum ultraviolet has a short wavelength (a range of 200-10 nanometers) that puts it at the far end of the ultraviolet portion of the electromagnetic spectrum. Today, VUV is absorbed by the oxygen in the atmosphere (hence its name). But in the early atmosphere, VUV from the Sun could have been producing oxygen out of then-abundant carbon dioxide.
Read 8 remaining paragraphs | Comments
#science
» see original post http://feeds.arstechnica.com/~r/arstechnica/science/~3/AgS7WI6w374/
See Zazzle gifts tagged with 'science'
No comments:
Post a Comment