Tag Archives: david catling

Book explains astrobiology for a general audience

In the late 1990s, the University of Washington created what was arguably the world’s first graduate program in astrobiology, aimed at preparing scientists to hunt for life away from Earth. In 2001, David Catling became one of the first people brought to the UW specifically to teach astrobiology.

Catling, a UW professor of Earth and space sciences, is the author of Astrobiology: A Very Short Introduction, the 370th offering in the Oxford University Press series of “very short introduction” books by experts in various fields. Catling was commissioned by editors to write the book, which was published in the United States on Jan. 1. Following are his answers to some questions about the book and astrobiology. (more…)

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Large Bacterial Population Colonized Land 2.75 Billion Years Ago

There is evidence that some microbial life had migrated from the Earth’s oceans to land by 2.75 billion years ago, though many scientists believe such land-based life was limited because the ozone layer that shields against ultraviolet radiation did not form until hundreds of millions years later.

But new research from the University of Washington suggests that early microbes might have been widespread on land, producing oxygen and weathering pyrite, an iron sulfide mineral, which released sulfur and molybdenum into the oceans. (more…)

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Fossil Raindrop Impressions Imply Greenhouse Gases Loaded Early Atmosphere

In ancient Earth history, the sun burned as much as 30 percent dimmer than it does now. Theoretically that should have encased the planet in ice, but there is geologic evidence for rivers and ocean sediments between 2 billion and 4 billion years ago.

Scientists have speculated that temperatures warm enough to maintain liquid water were the result of a much thicker atmosphere, high concentrations of greenhouse gases or a combination of the two. (more…)

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