Gliese 570 ABC’s habitable zones and how viruses created our oxygen supply

Welcome! “Alien Life” tracks the latest discoveries and thoughts in the various elements of the famous Drake Equation. You may notice that this and future entries are shorter than usual; career, family and book deal commitments have forced me to cut back some of my projects. Now, here’s today’s news:
g Stars - What would be the habitable zone for the stars in the nearby trinary Gliese 570 ABC? See article.
g Abodes - If the Earth was slightly smaller and less massive, life may have never gained a foothold on our planet. A new study shows that when searching for habitable planets around distant stars, astronomers might need to focus on planets Earth-sized or larger. See article.
g Life - New research shows that viruses infecting microorganisms in Earth's oceans might ultimately be responsible for much of the oxygen produced on our planet. The study highlights important links between life and the global climate of Earth. See article.
g Aftermath - Douglas Vakoch is one of a relatively small collection of scientists addressing the question of how to talk back to extraterrestrials. While most researchers involved in the Search for ExtraTerrestrial Intelligence come from physics and engineering backgrounds, Vakoch draws on a background in linguistics, sociology and psychology to explore SETI-related issues. Here’s an interview with him from Aug. 2003 about communicating with ET. See article.