Best Selling Books by Sarah Stewart Johnson

Discover best selling books by Sarah Stewart Johnson from local library. Read book reviews and check book availability from public library with one click.

For more book recommendations, please check out New York Times® Best Sellers, Children's Book Recommendations or the complete list of Featured Book Lists and Award Winners

Share
1 - 2 of 2 results

The Sirens of Mars

release date: Jul 20, 2021
Check price
The Sirens of Mars
Mars was once similar to Earth, but today there are no rivers, no lakes, no oceans. Yet multiple spacecraft are circling Mars, sweeping over Terra Sabaea, Syrtis Major, the dunes of Elysium, and Mare Sirenum-- on the brink, perhaps, of a staggering find. Johnson tells the story of how she and other researchers have scoured Mars for signs of life. She interlaces her journey as a female scientist with tales of other seekers, to offer an unlikely natural history of a place where no human has ever set foot, while providing a vivid portrait of our quest to defy our isolation in the cosmos. -- adapted from jacket

Mars in the Late Noachian

release date: Jan 01, 2008
Check price
Mars in the Late Noachian
This dissertation addresses whether simple life forms might have existed on Mars during the late Noachian epoch, and whether those life forms, or their traces, can be detected today. It begins by analyzing the ancient Martian climate in light of new evidence that sulfur chemistry played a prominent role in the planet's early evolution. It finds that sulfur-induced greenhouse warming could have periodically heated the planet enough to support liquid water, thereby creating warm, wet, clement conditions. Moreover, it finds that those warming pulses, while short-lived over geologic time, may have persisted for hundreds of years. If sulfur helped create environmental conditions capable of hosting life, however, it also created conditions that were adverse to sustaining it. In particular, dissipation of sulfur volatiles cooled the climate, and sulfur rainout contributed to the acidity of Martian surface waters. The dissertation therefore proceeds to analyze the potential for persistence and detection of life in terrestrial environments with Mars-like characteristics. It first investigates the potential for detecting ancient life by searching for lipid biomarkers in sulfur-rich acid salt lakes, concluding that a variety of biomarkers may be more resistant to decay than previously believed. It then analyzes soil samples from permafrost, discovering the oldest independently authenticated viable organisms ever found, and positing low-level metabolic activity and DNA repair as a survival mechanism in ancient cells. Finally, the dissertation uses deep sequencing to examine prokaryotic diversity in a terrestrial Mars-like river characterized by low pH and high concentrations of iron and sulfur, with results considered in light of the implications for life detection approaches incorporating new, in situ "PCR in a chip" technology. The dissertation concludes by proposing future work, including the ultimate goal of developing a life detection instrument for Mars.


  • Aboutread.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising a program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.

  • Copyright © 2021 Aboutread.com