Smaller asteroid than thought likely hit Tunguska and listening for alien radio and television broadcasts

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 Abodes - Researchers have found that a smaller asteroid than previously thought caused the destructive 1908 Tunguska impact in Siberia. The finding is helping scientists determine the amount of damage small asteroids can potentially cause to ecosystems and human populations. See article.
g Life - Scientists have discovered that genes have the ability to recognize similarities in each other from a distance and without other biological molecules aiding in the process. The unique discovery may help explain how similar genes group together and perform key processes involved in evolution. See article.
g Message - Avi Loeb of the Harvard Smithsonian Center for Astrophysics has proposed a radically new type search for extraterrestrial intelligence. Instead of looking for a beacon, he suggested, we should rather look for normal electromagnetic signals that are produced by a civilization such as our own. In our case these would include radio and television broadcasts, as well as military radar signals that are the strongest of all. According to Loeb it is reasonable to expect that alien civilizations also produce these types of electromagnetic signals that spill out naturally into space. Most importantly, he argued, we will soon be in a position where we can eavesdrop on them. See article.
g Aftermath - These are intriguing times in the exploration of other solar-system bodies. Continuing discoveries about life on Earth and the return of data suggesting the presence of liquid water environments on or under the surfaces of other planets and moons have combined to suggest the significant possibility that extraterrestrial life may exist in this solar system. Similarly, not since the Viking missions of the mid-1970s has there been as great an appreciation for the potential for Earth life to contaminate other worlds. Current plans for the exploration of the solar system include constraints intended to prevent biological contamination from being spread by solar-system exploration missions. See article.