Galaxies just passing through, musings on the autumnal equinox and guiding SETI’s efforts

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 - Two dwarf galaxies thought to be our Milky Way's longtime companions are actually relative newcomers to our neighborhood that are just passing through, according to a new study. See article.
g Abodes - Scientists on the Cassini mission are poring through hundreds of images returned from last week’s flyby of Saturn's two-toned moon Iapetus. Pictures show the moon's yin and yang – a white hemisphere resembling snow, and the other as black as tar. See article.
g Life - The study of biodiversity and astrobiology share the common thread of viewing the planet as a whole and attempting to see its future by examining its past. The present moment in history has been characterized as the first time in which one species - humans - are in one way or another 'responsible' for the entire biosphere: changing it, maintaining it, and of course, possibly extinguishing it. According to the World Wildlife Fund, the Earth is losing species at a rate not seen for 65 million years, since the extinction of the dinosaurs. As Harvard professor of evolutionary biology, Andrew Knoll, remarked: " [For astrobiology] everything we know about life in the universe comes from life on Earth. In a sense, putting current diversity at peril for those who would like to understand biology as a planetary phenomenon is like burning a library." See article. Note: This article is from 2003.
g Intelligence - As if awakening from a long slumber, each September the harvest moon rises out of the plain and into our collective consciousness. It's something that people of the land have relied on for guidance through the centuries. See my musings on the autumnal equinox, published during 2003.
g Message - Where would you look for extraterrestrial life? Here’s a paper that helps guide SETI’s efforts. Note: This piece is a decade old.
g Cosmicus - Book alert: If you want to read a book that delves into the potential of bases at the lunar poles, have a look at "Moonrush" by Dennis Wingo.
g Learning - Here’s a neat interactive Web site for kids: “Are Humans All Alone in the Universe?” In the program, kids get to search for ET — and learn some principles of science along the way. See article.
g Imagining - Like first contact stories? Then be sure to read Nick Pollotta and Phil Foglio’s novel “Illegal Alien,” published by TSR in 1988.
g Aftermath - Extraterrestrials might display either or both of two types of altruism: reciprocal altruism and nepotism. In reciprocal altruism, nice-ness is reciprocated with nice-ness, negativity with negativity. Reciprocal altruism is seen, for example, in chimpanzee grooming and food sharing. If Chimp A grooms Chimp B, Chimp A often gets a payback at dinner assuming no more than a couple hours has passed between personal hygiene and meal time. Even reciprocity has its limits such as those imposed by the constraints of memory. In nepotism, by contrast, altruism is extended to one's close relatives, not necessarily with the expectation of direct payback. Rather, by helping relatives, indirectly the altruist also benefits. By increasing the chances that relatives will survive to reproduce, the altruists genes also have an increased chance of being passed on to the next generation, simply because close relatives share a predictable percentage of genes, depending on how closely they are related. Nepotism may be even more common than reciprocal altruism in intelligence beyond Earth. See article. Note: This article is from 2003.