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Exoplanets

Oxygen not evidence for exoplanet 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: There are millions of habitable planets… no

Here. But now this: It is most likely that we are the only living beings in our galaxy, according to an esteemed former Nasa scientist. William Borucki, who played a large part in finding other potentially hospitable planets during his role as chief investigator for the US space agency’s Kepler mission until his retirement in 2015, said that the evidence points to us being alone, in our galaxy at least. Definitely don’t blast off just yet. See also: Don’t let Mars fool you. Those exoplanets teem with life! and How do we grapple with the idea that ET might not be out there?

Millions more planets theoretically habitable?

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 ›

Oxygen Does Not Equal Life – Implications for Abiogenesis?

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 ›

Ancient sub seafloor life and ET life

 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 ›

Team finds Earth’s mineralogy is unique in cosmos

From ScienceDaily: New research predicts that Earth has more than 1,500 undiscovered minerals and that the exact mineral diversity of our planet is unique and could not be duplicated anywhere in the cosmos. Wouldn’t that b bad news to the cosmos-a-minute/fund us!! crowd? Minerals form from novel combinations of elements. These combinations can be facilitated by both geological activity, including volcanoes, plate tectonics, and water-rock interactions, and biological activity, such as chemical reactions with oxygen and organic material. Nearly a decade ago, Hazen developed the idea that the diversity explosion of planet’s minerals from the dozen present at the birth of our Solar System to the nearly 5,000 types existing today arose primarily from the rise of life. More than Read More ›

Earth is outside habitable zone?

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 ›

Water worlds can’t host life?

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 ›

Paul Davies: Search for alien life on Earth

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 ›

Rob Sheldon on Earth-like conditions and life

Further to NASA says new Earth-like planet found (which may or may not be actually Earth-like), the question was raised, “Is there an accepted hypothesis on the subject of whether Earth-like conditions are essential to life?” Physicist Rob Sheldon writes to say, Like most other things involving life, NASA is schizophrenic about the subject. Darwinists say that life ought to be springing up everywhere that conditions permit. But then when their initial exuberance is not rewarded, the excuse is that conditions are not permitting. But Darwinists can’t have it both ways. Either Origin-of-life (OOL) is tough and the Earth is miracle, or it is easy, really really easy and Earth is nothing special. If life sprang up on Earth between Read More ›

Oops. New Kepler planet NOT like Earth?

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 ›

NASA says new Earth-like planet found

Here: Nasa scientists have announced the discovery of Kepler 452b, also known as ‘Earth 2.0’, an earth-like planet in our galaxy. Over the course of years of data-gathering by the Kepler space telescope and even more analysis and work here on Earth, scientists confirmed the existence of the distant exoplanet, which is the most earth-like planet ever discovered. Although the planet is far too far away to photograph, advanced Nasa technology means we know a surprising amount about this ‘New Earth’. Earlier this year, there were eight of them. We shall see. The new planet is slightly larger than Earth, and is estimated to have twice the gravitational pull of our own planet. However, according to the scientists on the Read More ›

Implications of the Privileged Planet Hypothesis

Over on the other thread we’ve had a brief discussion of the recent initiative to find extraterrestrial intelligence. In response to a couple of the comments I thought it might be instructive to look at the logic behind the privileged planet hypothesis, as it relates to the search for life beyond Earth. To that end, I pose the following: What is the implication of the Earth being a Privileged Planet, assuming we subscribe to that view? Does it mean: (a) that Earth (with all of its various characteristics) is unlikely to have come about by purely natural means; and/or (b) that Earth is unique (or nearly unique) in the galaxy or the cosmos? —– The reason I pose the question Read More ›

Renewed Search for ET – $100M Initiative

Today, Yuri Milner and Stephen Hawking announced a $100M initiative to seek extraterrestrial life, injecting renewed energy (and funds) into the hunt for life (specifically, intelligent life) beyond our fair planet. Although this has been a decades-long area of research and interest, with the SETI institute playing perhaps the most important role in recent years, this new initiative promises to engage many more researchers and to create “the most ambitious and robust SETI program yet performed.” Observations should begin as early as 2016. The introductory video is available here: http://www.washingtonpost.com/posttv/national/health-science/breakthrough-initiatives-introduces-new-search-for-extraterrestrial-life/2015/07/20/d0d7a1b2-2eed-11e5-818f-a242f28e7022_video.html Additional information is available in several locations, including here: http://www.scientificamerican.com/article/stephen-hawking-and-yuri-milner-announce-100m-initiative-to-seek-extraterrestrial-intelligence/ http://www.ucolick.org/news/initiative-apf.html

So the carbon layer isn’t magic either?

From Ars Technica: Sometimes, scientists announce things that are breathtakingly stupid. The Guardian, which generally has pretty good science coverage, has an article up reporting that some top scientists believe that the comet 67P may harbor lots and lots of life. The purported evidence for life is the presence of complex hydrocarbons on the comet’s crust. Of course, this article is just based on a press release, and the data won’t be available until it’s presented later today at a meeting of the Royal Astronomical Society. But The Guardian could at least have done some background reading on the person behind the claim, Chandra Wickramasinghe. It would have found that he has a long history of making claims about extraterrestrial Read More ›