Extraterrestrial life

Further to: There are millions of habitable planets… no and Rob Sheldon reflects on the hunt for water on Mars, we now hear  from Space.com: Oxygen on Exoplanets May Not Mean Alien Life On Earth, plants release oxygen into the air through photosynthesis. If a planet beyond the solar system was found to contain oxygen in its atmosphere, scientists reasoned, that oxygen would have formed as a byproduct of life. Narita and his team decided to study the role of stellar radiation around stars similar to the sun. They found that, if enough of the mineral titania lay on the surface of a planet, it could dissolve in liquid water, producing oxygen in the atmosphere. Titania is a naturally occurring Read More ›

Further to the recent evidence for water on Mars, and the BBC News commentary that “If we find life on Mars and it can be shown to be of a different origin to that on Earth, then that essentially means that the Universe is teeming with life. It seems almost impossible that life could spring up by chance on two adjacent planets if life was rare.” Actually, that doesn’t follow at all. It’s like saying that if there are several species of monotreme mammals in Australia, they must be common all over the planet. They are not. If one doesn’t know the history, one cannot really insist on things like that. Meanwhile, Rob Sheldon reminisces: — I had lunch with Read More ›

The first clue for caution is this should be the title: Theoretical astrophysicists have discovered that millions of planets are more habitable than we realized The authors, led by Jérémy Leconte, a postdoctoral fellow at the Canadian Institute for Theoretical Astrophysics at the University of Toronto, built a three-dimensional climate model and found that a thin atmosphere would allow a planet to break free of rotational lockup and spin as it rotates around the star. Scientists previously thought that only a large atmosphere could create a significant spin but, according to Leconte, thin atmospheres may have a larger rotational effect, because they allow more light from the star to reach the planet’s surface. This solar heat drives wind to create Read More ›

Every publication should be special right? From New Scientist: Earth’s composition might be unusual for a planet with life Is Earth the odd planet out? Many of our galaxy’s habitable planets probably have a chemical composition that is quite different from Earth’s. More. So let’s get this straight: The only planet that we know has life (because we are awash in it) has a different chemical composition from planets that some people believe might have life (but maybe not, or we’ll never find out)? So it comes down to fact vs. speculation. In which business would you invest your pension? How did pop science get to be just SOOO nuts? See also: Copernicus, you are not going to believe who Read More ›

The Japanese National Institutes of Natural Sciences (NINS) are reporting about new research that throws a small wrinkle into the search for life on planets outside our solar system. Such bodies, known as “exoplanets,” have emerged as one of the more exciting areas of astronomical study — an entire new field of research having essentially arisen in little more than two decades and now occupying many full-time researchers, several earth-bound telescopes, and even dedicated space missions. Early results have been impressive, with the improvements in sensor technology matched by the exponential increase in discovered bodies. After the first lone exoplanet was discovered around a main sequence star in 1995, a small trickle of additional exoplanets were discovered. Then the trickle Read More ›

It would be so much more fun. From ScienceDaily: Earth’s extremes point the way to extraterrestrial life: Exploring the limits of life in the universe NASA’s discovery last month of 500 new planets near the constellations Lyra and Cygnus, in the Milky Way Galaxy, touched off a storm of speculation about alien life. In a recent article in the journal Life, Schulze-Makuch draws upon what is known about Earth’s most extreme lifeforms and the environments of Mars and Titan, Saturn’s moon, to paint a clearer picture of what life on other planets could be like. His work was supported by the European Research Council. “If you don’t explore the various options of what life may be like in the universe, Read More ›

 From Wood’s Hole: Ancient rocks harbored microbial life deep below the seafloor, reports a team of scientists from the Woods Hole Oceanographic Institution (WHOI), Virginia Tech, and the University of Bremen. This new evidence was contained in drilled rock samples of Earth’s mantle – thrust by tectonic forces to the seafloor during the Early Cretaceous period. The new study was published today in the Proceedings of the National Academy of Sciences. The discovery confirms a long-standing hypothesis that interactions between mantle rocks and seawater can create potential for life even in hard rocks deep below the ocean floor. The fossilized microbes are likely the same as those found at the active Lost City hydrothermal field, providing potentially important clues about Read More ›

Physicist Rob Sheldon attended the 17th SPIE Astrobiology Conference (San Diego, 9 – 13 August 2015, and kindly writes to report, The conference was begun in 1996 when the late David McKay, a meteoriticist from NASA Johnson SFC in Houston, examined a meteorite collected from an expedition to the Allen Hills of Antarctica. The Japanese had discovered that meteorites that land in Antarctica are carried by the ice flow to the foot of mountains where the ice evaporates and meteorites collect. The harvest from annual expeditions are catalogued and stored in Houston, and ALH84001 was the first one collected on this trip.   =============================================== So this conference was initiated by then SPIE president Richard Hoover, as a forum to present Read More ›

Well, first, the BBC asks: What makes a planet habitable? Here: Water in liquid form is thought to be a necessity for life on Earth. Based on this, let’s look at the classical definition for the habitable zone as the region around a star, such as our own Sun, where the temperature of any orbiting planet permits water in liquid form. But, as it happens, there are difficulties. What if the planet sports a blanket of white clouds? Clouds are reflective and therefore will cool the planet, acting to push the habitable zone closer to the star. Amusingly, if we calculate this “equilibrium temperature” for the Earth, taking into account its beautifully reflective clouds, then it turns out that we Read More ›

From Science: Why water worlds won’t host life New research published online before print in the Monthly Notices of the Royal Astronomical Society shows that Earth-sized water worlds are habitable only in a very limited range of temperatures—from about 0̊C to 127̊C. Anything outside that range, which tends to occur on planets that are in a “Goldilocks zone” of 102 million to 140 million miles away from their stars (Earth is about 93 million miles away from the sun), could be devastating for life as we know it. More. Here’s the abstract: The unstable CO2 feedback cycle on ocean planets Ocean planets are volatile-rich planets, not present in our Solar system, which are thought to be dominated by deep, global Read More ›

First, we hear something sensible: Paul Davies: Search for alien microbial life on Earth: (= He advocates a search for evidence where there is a good chance it may be found, instead of the usual faint hope feeding frenzy and unmoored speculation.) Now, just to prove silly season is here, we also learn the latest hot weather story abut intelligent aliens from New Statesman: Be careful what you say to aliens Seeking alien contact could be the thing that triggers our own implosion. … But even the benign scenarios about alien signals could be disruptive, in Davies’s view. Knowledge from an advanced civilisation would “change the economic and technological balance of the planet”, he says. And that’s what makes the Read More ›

Further to: Physicist Paul Davies’ killer argument against the multiverse (Vincent, Torley), here’s physicist and author Davies on the search for extraterrestrial life: A huge investment into the search for intelligent alien life has renewed public interest in the question of whether we’re alone in the universe. Paul Davies tells Late Night Live why he’s sceptical of the current search, and why he thinks we should look for ‘life as we don’t know it’ on our own planet. … Professor Davies is a supporter of the search for extraterrestrial intelligence (SETI)—in fact, he’s chair of the SETI Post-Detection Science and Technology Task Group, the body charged with responding if Earth is contacted by aliens. However, he thinks we may need Read More ›

That is, why inferring design on functionally specific, complex organisation and associated information, e.g.: and equally: . . . makes good sense. Now, overnight, UD’s Newsdesk posted on a Space dot com article, Is Our Universe a Fake? The article features “Philosopher Nick Bostrom, director of the Future of Humanity Institute at Oxford University.” I think Bostrom’s argument raises a point worth pondering, one oddly parallel to the Boltzmann brain popping up by fluctuation from an underlying sea of quantum chaos argument, as he discusses “richly detailed software simulation[s] of people, including their historical predecessors, by a very technologically advanced civilization”: >>Bostrom is not saying that humanity is living in such a simulation. Rather, his “Simulation Argument” seeks to show Read More ›

We understand; they need the money. But get this: NASA ‘on the Cusp’ of Being Able to Answer if We’re Alone in the Universe Chairman says Obama’s funding level “would slow the rate” of missions like the Pluto flyby. More. Are we alone? It’s not an honest question because NASA would never accept a positive answer, as in: Yes we are alone. And we will never be sure if any answer is available either. That’s fine, and no one here says they shouldn’t be funded. But could they spare us this stupidity? Maybe we are not always the fools they take us for. Don’t let Mars fool you. Those exoplanets teem with life! But surely we can’t conjure an entire Read More ›

Further to: NASA says new Earth-like planet found: from Real Clear Science: Another problem is that Kepler-452b is alone. As far as we know, there are no other planets in the same system. This is an issue because it was most likely our giant gas planets that helped direct water to Earth. At our position from the sun, the dust grains that came together to form the Earth were too warm to contain ice. Instead, they produced a dry planet that later had its water most likely delivered by icy meteorites. These frozen seas formed in the colder outer solar system and were kicked towards Earth by Jupiter’s huge gravitational tug. No Jupiter analogue for Kepler-452b might mean no water Read More ›