Building DNA through chemistry rather than biology, Chinese lunar probe and mind-boggling aftermath of discovering we’re either alone or part of life-

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 - How are stars classified into different categories? In astronomy, stellar classification is a classification of stars based initially on photospheric temperature and its associated spectral characteristics, and subsequently refined in terms of other characteristics. See article. For related item, see this explanation of the Hertzsprung-Russell diagram.
g Abodes - A new study casts doubt on the theory that an asteroid or meteor impact caused the greatest mass extinction in Earth's history. The research shows that environmental stress due to global warming and volcanic eruptions may have been the culprit. See article.
g Life - Scientists have suggested a new theory for how the chemical constituents essential to life arose on the early Earth. They've shown that simple molecules can combine to form the building blocks of DNA through chemistry rather than biology. See article.
g Cosmicus - Last month, the Chinese National Space Administration launched Chang'e-1, the first step in China's efforts to land robot explorers on the Moon. From orbit, the Chang'e-1 spacecraft will collect geological data and the first detailed images of some regions near the lunar poles. See article.
g Aftermath - Finding out that we are alone in the universe or a suburb of a huge village of other star folk - either alternative is mind boggling. See article. Note: This article is from 2003.