Extraterrestrial life

From Mike Wall at Space.com: For starters, HD 189733b is much bigger and hotter than Earth; it’s about the size of Jupiter and zips around its host star in just 2.2 Earth days. That orbit is so close that the exoplanet is probably tidally locked, always showing one face to its star, just as the moon always shows one face (the near side) to Earth. And then there’s the weather. The winds on HD 189733b (which lies about 63 light-years from Earth, in the constellation Vulpecula) blow at up to 5,400 mph (8,700 km/h) — about seven times the speed of sound. And if that’s not crazy enough for you, scientists think the rain on this world is made not Read More ›

At NDPI Life: The Cosmic Zoo: The (Near) Inevitability of the Evolution of Complex, Macroscopic Life William Bains and Dirk Schulze-Makuch Abstract: Life on Earth provides a unique biological record from single-cell microbes to technologically intelligent life forms. Our evolution is marked by several major steps or innovations along a path of increasing complexity from microbes to space-faring humans. Here we identify various major key innovations, and use an analytical toolset consisting of a set of models to analyse how likely each key innovation is to occur. Our conclusion is that once the origin of life is accomplished, most of the key innovations can occur rather readily. The conclusion for other worlds is that if the origin of life can Read More ›

We are not making this up. (It’s the time of year, see?) From Cheyenne MacDonald at Daily Mail: It’s now known that the living conditions in space can wreak havoc on the human body – but how might the human body leave its mark on the cosmos? Plans for more rigorous missions have increased the likelihood for the eventual death of an astronaut in space, and scientists now say it’s possible that a rogue corpse could provide the spark for life on another planet. While the conditions would have to be ‘ideal,’ a human body that manages to avoid incineration in the atmosphere and lands on a distant world could transport microbes or even act as the ‘starter-pack’ for the Read More ›

From Phys.org: In 1976, two Viking landers became the first US spacecraft from Earth to touch down on Mars. They took the first high-resolution images of the planet, surveyed the planet’s geographical features, and analyzed the geological composition of the atmosphere and surface. Perhaps most intriguingly, they also performed experiments that searched for signs of microbial life in Martian soil. Overall, these life-detection experiments produced surprising and contradictory results. One experiment, the Labeled Release (LR) experiment, showed that the Martian soil tested positive for metabolism—a sign that, on Earth, would almost certainly suggest the presence of life. However, a related experiment found no trace of organic material, suggesting the absence of life. With no organic substances, what could be, or Read More ›

From Astronomical Journal: In order to search for evidence of hydration on M-type asteroid (16) Psyche, we observed this object in the 3 micron spectral region using the long-wavelength cross-dispersed (LXD: 1.9-4.2 micron) mode of the SpeX spectrograph/imager at the NASA Infrared Telescope Facility (IRTF). Our observations show that Psyche exhibits a 3 micron absorption feature, attributed to water or hydroxyl. The 3 micron absorption feature is consistent with the hydration features found on the surfaces of water-rich asteroids, attributed to OH- and/or H2O-bearing phases (phyllosilicates). The detection of a 3 micron hydration absorption band on Psyche suggests that this asteroid may not be metallic core, or it could be a metallic core that has been impacted by carbonaceous material Read More ›

From John Wenz at Astronomy News: It’s (probably) not aliens, yet again. The slightest whiff of aliens is enough to send the public into a frenzy. There have been quiet rumblings after a pre-print paper was released on ArXiv from two French-Canadian researchers who interpreted certain sky signal data to be possibly of intelligent extraterrestrial origin. But “Apparently several — more than three or four — referees have been disinclined to see this published,” Seth Shostak, senior astronomer at the SETI Institute says in an email. “I am quite skeptical, in particular of the data processing that can take spectrally sampled data, and infer time variations. So I’d be a little careful.”More. We can be sure that if there were Read More ›

Starting this month. From Ross Logan at UK Mirror: The Five-hundred-metre Aperture Spherical Telescope (FAST) will search deep space in the hope of unlocking some of the universe’s deepest secrets Is Earth finally about to make contact with extra terrestrial life? That is one of the hopes for the world’s largest radio telescope, which will be switched on later this month. The finishing touches have now been put to the Five-hundred-metre Aperture Spherical Telescope (FAST), in south west China’s Guizhou Province, with the enormous 1,650-foot-wide dish set become operational from September 25. More. Good hunting! But one question that arises is, how do we know at what point we can come to a conclusion? See also: How do we grapple Read More ›

From evolutionary biologist Matthew Wills at RealClearScience: Ultimately, the jury is out on the extent to which intelligent aliens – if they exist – would resemble us. It may or may not be significant that humans have just two eyes and ears (just enough for stereo vision and hearing), and just two legs (reduced from the initially more stable four). Many other organs also come in pairs as a consequence of our evolutionarily deep-seated – and perhaps inevitable – bilateral symmetry. Still other elements of our body plan are probably nothing more than chance. The fact that we have hands and feet with five digits is a consequence of the fixation on five in our early tetrapod ancestors – close Read More ›

But he has gotten used to it. From Chau Tu at ScienceFriday: More than 50 years later, the renowned astronomer is surprised by the cultural impact of his Drake Equation. No one else is. What might be the next best ‘candidate’ on Earth for gaining intelligence? There’s an obvious one, the chimpanzees. Or the bonobo—that’s the closest thing in physiology and social life to humans, so the bonobos are the prime candidate for our successor, if we ever wipe ourselves out or allow ourselves to be wiped out. If the planet gave them a million years to evolve, they would become us. Another creature I always cite, which is half-joke and half-serious, is squirrels. If you look at the fossil Read More ›

From Nature: At the Massachusetts Institute of Technology in Cambridge, astronomer Sara Seager has begun to examine 14,000 compounds that are stable enough to exist in a planetary atmosphere. She and her colleagues are winnowing down their initial list of molecules using criteria such as whether there are geophysical ways to send the compound into the atmosphere. “We’re doing a triage process,” says Seager. “We don’t want to miss anything.” The Seattle meeting aims to compile a working list of biosignature gases and their chemical properties. The information will feed into how astronomers analyse data from NASA’s James Webb Space Telescope, slated for launch in 2018. The telescope will be able to look at only a handful of habitable planets, Read More ›

From Ethan Siegel at Forbes: The first test was performed first, and came back negative. The second test was next, and also came back negative. By time the third test was performed, with both landers in situ, the prospects were pretty grim, but the data was taken anyway. To the surprise of almost everyone, both Viking 1 and 2 detected metabolized, radioactive carbon-14 as part of the carbon dioxide emitted. They even took their samples from different locations: one from soil in direct sunlight, the other from soil found under a rock. In both samples, the carbon dioxide emission was immediate and sustained after the first injection. To great excitement and fanfare, the team led by Gilbert Levin thought they Read More ›

Asks Adam Frank: Earlier this year, my colleague Woody Sullivan and I published a paper in the journal Astrobiology presenting new results that, I believe, throw new light on the ancient question. And, based on that work, last month I wrote an OpEd in The New York Times that ran with provocative title “Yes, There Were Aliens.” The Times piece found a large audience and generated strong responses running from agreement to dissent to folks telling me I really should look into UFOs (sorry, not my thing). Just what he’s got against the UFOs is not, under the circumstances, clear. But anyway, One of the principle objections raised to my piece was that the fact that just because 10-22 is Read More ›

Despite the fact that, as noted earlier, “Aliens are real. And astrobiology is exceedingly rigorous,” there are doubters like Ethan Siegel at Forbes: There may never have been another intelligent, technologically advanced alien species in the entire history of the Universe. Last week, in the New York Times, scientist Adam Frank emphatically wrote that Yes, There Have Been Aliens, concluding that given all the potentially habitable worlds we know must be out there from our astrophysical discoveries, intelligent life must have arisen. What he fails to account for, however, is the magnitude of the unknowns that abiogenesis, evolution, long-term habitability and other factors bring into the equation. Although it’s true that there are an astronomical number of possibilities for intelligent, Read More ›

From Adam Frank at New York Times: You might assume this probability is low, and thus the chances remain small that another technological civilization arose. But what our calculation revealed is that even if this probability is assumed to be extremely low, the odds that we are not the first technological civilization are actually high. Specifically, unless the probability for evolving a civilization on a habitable-zone planet is less than one in 10 billion trillion, then we are not the first. To give some context for that figure: In previous discussions of the Drake equation, a probability for civilizations to form of one in 10 billion per planet was considered highly pessimistic. According to our finding, even if you grant Read More ›

From Ross Andersen at Atlantic: We can’t extrapolate from our experience on this planet, because it’s only one data point. We could be the only intelligent beings in the universe, or we could be one among trillions, and either way Earth’s natural history would look the exact same. … We certainly don’t have grounds to say that the “odds are high” that some civilization preceded ours, or enough evidence to suggest that skepticism about the possibility “borders on the irrational.” More. That’s the trouble. 1 is not a good number to work with when assessing probability. See also: NASA “shameful” in not looking harder for alien life? Are these people willing to grasp the possibility that we might BE alone? Read More ›