Extraterrestrial life

From philosopher Tim Mulgan at Aeon: In academic philosophy today, an interest in extraterrestrial life is regarded with some suspicion. This is a historical anomaly. In Ancient Greece, Epicureans argued that every possible form of life must recur infinitely many times in an infinite universe. In the 17th, 18th and 19th centuries, as modern astronomy demonstrated that our Earth is just another planet and our Sun just another star, the default hypothesis among informed observers was that the Universe is filled with habitable planets and intelligent life. One principal argument for this ‘pluralism’ was philosophical or theological: God (or Nature) does nothing in vain, and therefore such a vast cosmos could not be home to only one small race of Read More ›

One eventually gets used to science claims with a lot of “may”s in them. From ScienceDaily: Fast-moving flows of interplanetary dust that continually bombard our planet’s atmosphere could deliver tiny organisms from far-off worlds, or send Earth-based organisms to other planets, according to the research. The dust streams could collide with biological particles in Earth’s atmosphere with enough energy to knock them into space, a scientist has suggested. Such an event could enable bacteria and other forms of life to make their way from one planet in the solar system to another and perhaps beyond. The finding suggests that large asteroid impacts may not be the sole mechanism by which life could transfer between planets, as was previously thought. Okay, Read More ›

And most don’t think life will be found on an exoplanet by 2040. From Alexandra Witze at Nature: It turns out that water worlds may be some of the worst places to look for living things. One study presented at the meeting shows how a planet covered in oceans could be starved of phosphorus, a nutrient without which earthly life cannot thrive. Other work concludes that a planet swamped in even deeper water would be geologically dead, lacking any of the planetary processes that nurture life on Earth. “Habitability is not only about finding the signature of an alien life form taking a deep breath,” says Elizabeth Tasker, an astronomer and exoplanet researcher at the Japan Aerospace Exploration Agency’s Institute Read More ›

From ScienceDaily: In a new study published in the International Journal of Astrobiology scientists from the University of Oxford show for the first time how evolutionary theory can be used to support alien predictions and better understand their behaviour. They show that aliens are potentially shaped by the same processes and mechanisms that shaped humans, such as natural selection. The theory supports the argument that foreign life forms undergo natural selection, and are like us, evolving to be fitter and stronger over time. Actually theories do not support arguments, they underlie them passively. Sam Levin, a researcher in Oxford’s Department of Zoology, said: ‘A fundamental task for astrobiologists (those who study life in the cosmos) is thinking about what extra-terrestrial Read More ›

No shortage of speculations as to where ET life might be hiding. From Mike Wall at LiveScience: E.T. may be out there, silently swimming in frigid oceans beneath miles and miles of ice. … Last week, planetary scientist Alan Stern offered up another idea: Maybe intelligent life is widespread throughout the galaxy but most of it lives in deep, dark subsurface oceans that are cut off from the rest of the cosmos. … For starters, Stern said, such buried oceans may be common across the Milky Way. Indeed, they should be, if our own solar system is any guide: Liquid-water oceans slosh beneath the frigid shells of the Jupiter moons Callisto, Ganymede and Europa, for example, as well as the Read More ›

Our new word for the weekend. From Ross Pomeroy at RealClearScience: Most thinkers, including famed astrophysicist Carl Sagan, agree that mathematics could serve as the foundation for our discussions. With that in mind, British scientist Lancelot Thomas Hogben rafted a language system called Astraglossa. Communicated over radio signals, short pulses called “dashes” would represent numbers, and longer batteries of pulses called “flashes” would represent mathematical symbols like addition or subtraction. Once the basics of arithmetic are established between our species, Hogben imagined moving the discussion on to astronomy, a hobby we would obviously both have in common. After all, two aliens species talking about space would probably be like two Earthlings talking about the weather. But maybe not. What if Read More ›

Due to more efficient technology, says SETI astronomer Seth Shostak at Nautilus: Most of our experiments so far have used large radio antennas in an effort to eavesdrop on radio signals transmitted by other societies, an approach that was dramatized by Jodie Foster in the 1997 movie Contact. Unlike other alien potboilers, Contact’s portrayal of how we might search for extraterrestrials was reasonably accurate. Nonetheless, that film reinforced the common belief that SETI practitioners paw through cosmic static looking for unusual patterns, such as a string of prime numbers. The truth is simpler: We have been searching for narrow-band signals. “Narrow-band” means that a large fraction of the transmitter power is squeezed into a tiny part of the radio dial, Read More ›

From Matt Williams at Universe Today: Recent studies have indicated that UV radiation may be necessary for the formation of ribonucleic acid (RNA), which is necessary for all forms of life as we know it. And given the rate at which rocky planets have been discovered around red dwarf stars of late (exampled include Proxima b, LHS 1140b, and the seven planets of the TRAPPIST-1 system), how much UV radiation red dwarfs give off could be central to determining exoplanet habitability. … As always, scientists are forced to work with a limited frame of reference when it comes to assessing the habitability of other planets. To our knowledge, life exists on only on planet (i.e. Earth), which naturally influences our Read More ›

From ScienceDaily: Daniel Whitmire, a retired astrophysicist who teaches mathematics at the University of Arkansas, once thought the cosmic silence indicated we as a species lagged far behind. “I taught astronomy for 37 years,” said Whitmire. “I used to tell my students that by statistics, we have to be the dumbest guys in the galaxy. After all we have only been technological for about 100 years while other civilizations could be more technologically advanced than us by millions or billions of years.” Recently, however, he’s changed his mind. By applying a statistical concept called the principle of mediocrity — the idea that in the absence of any evidence to the contrary we should consider ourselves typical, rather than atypical — Read More ›

From Casey Smith at National Geographic: In essence, the researchers say, only the death of the sun will ultimately lead to the total extinction of life on Earth, including tardigrade [water bears]. “It seems that life, once it gets going, is hard to wipe out entirely,” Sloan says. “Huge numbers of species, or even entire genera, may become extinct, but life as a whole will go on.” And that’s an encouraging message for scientists seeking signs of life beyond our planetary shores. “Tardigrades are as close to indestructible as it gets on Earth,” Alves Batista says, “but it’s possible that there are other resilient species examples elsewhere in the universe.” More. Provided, that is, it can get started there. Someone should tell Read More ›

From Charlie Martin at PJ Media: Hawking is certainly the most famous theoretical physicist since Albert Einstein, and rightly so, as he’s been very creative, developed theoretical ideas that have turned out to explain real physical observations — as well a a lot which haven’t been physically verified — and has done so while setting an apparent world record for the longest-surviving Lou Gehrig’s disease patient. This means that anything Hawking says about any scientific topic is news. On the other hand, that doesn’t make it right, especially as he strays beyond the edges of his own field. Recently, he has been doomsaying about artificial intelligence as well as carbon dioxide and evil alien intelligences. Re the latter (2010): Even Read More ›

From Elizabeth Howell, at Space.com: Would it be easy to determine if the source of a mysterious radio signal was aliens? Probably not. A new paper argues that contact with extraterrestrials will likely be discovered through a prolonged, incremental process rather than an instantaneous eureka-like moment. Eureka — what the ancient Greek mathematician Archimedes allegedly said when he cracked a tough science problem about water displacement — tends to be the exception in science rather than the rule. … Cirkovic said in an email that the community involved in the search for extraterrestrial intelligence (SETI) should instead be prepared for a process that would take a very long time. It may take decades as the SETI community looks at all Read More ›

From Ian Crawford at Space.com: Beyond the more narrowly intellectual benefits of astrobiology are a range of wider societal benefits. These arise from the kinds of perspectives – cosmic in scale – that the study of astrobiology naturally promotes. It is simply not possible to consider searching for life on Mars, or on a planet orbiting a distant star, without moving away from the narrow Earth-centric perspectives that dominate the social and political lives of most people most of the time. Today, the Earth is faced with global challenges that can only be met by increased international cooperation. Yet around the world, nationalistic and religious ideologies are acting to fragment humanity. At such a time, the growth of a unifying Read More ›

From astrophysics prof Geraint Lewis at New Scientist: What if aliens are out there after all, only they are sleeping, awaiting a glorious future when the universe is cooler, providing the right conditions for them to fulfil their ultimate ambitions? According to this new idea, alien civilisations emerged and flourished in the early universe, growing in size and developing technology to harness the energy from stars and galaxies. Eventually, after material expansion, these aliens would turn to more philosophical musings, pondering the big questions of the cosmos. Lewis spots flaws in the hypothesis and suggests, It is little more than guesswork and speculation. There is nothing wrong with a bit of speculation, it can inspire new thinking and new solutions, Read More ›

From Mike Wall at Space.com: A strange radio signal that seemed to emanate from a small nearby star probably came from Earth-orbiting satellites, astronomers say. Late last week, researchers announced that, on May 12, the 1,000-foot-wide (305 meters) Arecibo radio telescope in Puerto Rico detected a bizarre radio signal in the vicinity of Ross 128, a red dwarf star that lies just 11 light-years from Earth. The signal was theoretically consistent with a transmission from an alien civilization, the astronomers said, though they stressed that hypothesis was “at the bottom of many other explanations.” More. Coffee: Not really. Psychologically, aliens were at the top of the list. And they are much more fun than any other explanation even if they Read More ›