Astrobiology. Astrobiology is the study of the origin, evolution, distribution, and future of life in the universe: extraterrestrial life and life on Earth.
This interdisciplinary field encompasses the search for habitable environments in our Solar System and habitable planets outside our Solar System, the search for evidence of prebiotic chemistry, laboratory and field research into the origins and early evolution of life on Earth, and studies of the potential for life to adapt to challenges on Earth and in outer space.[2] Astrobiology addresses the question of whether life exists beyond Earth, and how humans can detect it if it does.[3] (The term exobiology is similar but more specific — it covers the search for life beyond Earth, and the effects of extraterrestrial environments on living things.)[4] Overview[edit] It is not known whether life elsewhere in the universe would utilize cell structures like those found on Earth.
(Chloroplasts within plant cells shown here.)[19] Alien Life More Likely on 'Dune' Planets, Study Suggests. Desert planets like the one depicted in the science fiction classic "Dune" might be the most common type of habitable planet in the galaxy, rather than watery worlds such as Earth, a new study suggests.
And that's not the only surprising result. The study also hints that scorching-hot Venus, where surface temperatures average 860 degrees Fahrenheit (460 degrees Celsius), might have been a habitable desert world as recently as 1 billion years ago. Galaxy should have been colonized by now. A recent article in the Economist alerted me to a recent paper by Thomas Hair and Andrew Hedman that profoundly reaffirms the conundrum that is the Fermi Paradox, an observational problem that is sometimes referred to as the Great Silence.
What's fascinating about the Hair and Hedman paper is that they are not cosmologists or astrobiologists, but rather mathematicians—and it is through the lens of number-cruching that they sought an answer to the question of how long it would take a civilization to colonize its local region given a specific set of parameters.
And their findings are disturbing: No matter how they reworked the numbers, they came to the same conclusion: the Galaxy should be colonized by now: To arrive at their conclusion Dr Hair and Mr Hedman assumed that outer space is dotted with solar systems, about five light years apart. Note: It doesn't appear that the Hair and Hedman paper is online; I have contacted them and asked for a copy or a link; stay tuned. The Fermi Paradox. SETI, the Fermi Paradox and The Singularity: Why our search for extraterrestial intelligence has failed. Faughnan Home | Contact Info | Site Contents | Search Rev: 30 May 2008.
Introduction The Fermi Paradox was first stated by Enrico Fermi in 1950 during a lunch time conversation. Fermi, a certified genius, used some straightforward math to show that if technological civilizations were common and moderately long-lived, then the galaxy ought to be fully inhabited [10]. The vast distances of interstellar space should not be a significant barrier to any such civilization --assuming exponential population growth and plausible technology. "Contact" should thus be completely inevitable; we ought to find unavoidable evidence of "little green men" all about us. Fermi paradox. A graphical representation of the Arecibo message – Humanity's first attempt to use radio waves to actively communicate its existence to alien civilizations The Fermi paradox (or Fermi's paradox) is the apparent contradiction between high estimates of the probability of the existence of extraterrestrial civilization and humanity's lack of contact with, or evidence for, such civilizations.[1] The basic points of the argument, made by physicists Enrico Fermi and Michael H.
Carl Sagan on Drake Equation. Alien Civilizations in Universe. Introduction This calculation is just a rough one because galaxies vary a lot.
There are also things called globular clusters that can contain hundreds of thousands of stars. I will be talking about type 0, type 1, type 2 and type 3 civilizations here. You might want to watch this video to understand exactly what that means: Kardashev scale civilizations, type 0,1,2,3 civilizations and beyond. Kardashev scale. The Kardashev scale is a method of measuring a civilization's level of technological advancement, based on the amount of energy a civilization is able to utilize.
The scale has three designated categories called Type I, II, and III. A Type I civilization uses all available resources impinging on its home planet, Type II harnesses all the energy of its star, and Type III of its galaxy. The scale is only hypothetical, but it puts energy consumption in a cosmic perspective. Kardashev scale civilizations, type 0,1,2,3 civilizations and beyond. The future of civilization & alien probes on moons. How Far Have Radio Signals Traveled From Earth? The expanding sphere of radio signals traveling outward from the earth is often portrayed in TV shows and Hollywood movies to be like a time machine.
The further you get from earth, the further back you go in the history of radio and TV broadcasts. Today we explore how far these signals have traveled, and more importantly, if radio signals actually work that way. Earth’s Expanding Radio Bubble. The Origin and Evolution of Life in the Universe. Exoplanet found… from another galaxy!! Today, astronomers announced that they have found a new exoplanet, a planet orbiting another star.
Nearly 500 exoplanets have been found in the past 15 years, so what’s the big deal, you may ask? The big deal is that this planet and star are from another galaxy! [Artist's impression of the alien planet; click to extragalaticate.] There is a whole lot of coolness going on here, so strap in. OK, first, this planet is in our own Milky Way galaxy. Is There Life Out There Somewhere In The Universe. Are there alien civilizations out there?
— Sorry this video is no longer available Are there alien civilizations out there? Sorry the above video is no longer available; and the author has been unable to find a satisfactory substitute video. In reality, we have hardly begun to explore our galaxy for intelligent life… the stars are simply too numerous and many are hidden by the mass or our own galaxies stars, dust and gas as we orbit on one of its edges. Take a moment to check out how big our universe really is Shortened link to this video: Take a moment to check out how big our universe really is [music, astronomy pictures]: Extraterrestrial life. Evolution Predictable Everywhere in the Universe, Scientist Says. Alien Civilizations in Universe. Drake equation. The Drake equation is a probabilistic argument used to estimate the number of active, communicative extraterrestrial civilizations in the Milky Way galaxy.
The equation was written in 1961 by Frank Drake not for purposes of quantifying the number of civilizations,[1] but intended as a way to stimulate scientific dialogue at the world's first SETI meeting, in Green Bank, West Virginia. The equation summarizes the main concepts which scientists must contemplate when considering the question of other radio-communicative life.[1] The Drake equation has proved controversial since several of its factors are currently unknown, and estimates of their values span a very wide range. This has led critics to label the equation a guesstimate, or even meaningless. History[edit] In September 1959, physicists Giuseppe Cocconi and Philip Morrison published an article in the journal Nature with the provocative title "Searching for Interstellar Communications.
The Possibility of Alien Life Is Now (Almost) Impossible to Deny. We could spot alien civilizations from the light of their cities. Why Can't We See Evidence of Alien Life? - Chris Anderson. Alien Planet "Full Documentary" Searching for Cost-Optimized Interstellar Beacons. Xenobiology. © 1981 Robert A. Freitas Jr. All Rights Reserved. Robert A. Freitas Jr., “Xenobiology,” Analog Science Fiction/Science Fact, Vol. 101, 30 March 1981, pp 30-41 URL: This paper contains material originally drawn from the book Xenology (1979) by Robert A. Xenology. 'Water Bears' Able To Survive Exposure To Vacuum Of Space. Of all environments, space must be the most hostile: It is freezing cold, close to absolute zero, there is a vacuum, so no oxygen, and the amount of lethal radiation from stars is very high. This is why humans need to be carefully protected when they enter this environment.
New research by Ingemar Jönsson and colleagues published in the September 9 issue of Current Biology, a Cell Press journal, shows that some animals —the so-called tardigrades or 'water-bears'— are able to do away with space suits and can survive exposure to open-space vacuum, cold and radiation. This is the first time that any animal has been tested for survival under open-space conditions. The test subjects were chosen with great care: Tardigrades —also known as water-bears— are tiny invertebrate animals from 0.1 to 1.5mm in size that can be easily found on wet lichens and mosses. How Incomprehensible Could Extraterrestrials Be? A few days ago Paul Gilster, the author of Centauri Dreams: Imagining and Planning Interstellar Exploration and the curator of Centauri Dreams , posted a thoughtful discussion of a blog entry I wrote (titled What's The Connection Between Deafness and SETI? ) His discussion and the resulting comments were fascinating, and in this post I want to carry on that conversation.
I want to ask: Will extraterrestrials be so different from us as to be truly incomprehensible? Abiogenesis. Researchers use Moore's Law to calculate that life began before Earth existed. "ET Technology Could Appear as Natural Objects in the Universe" According to the British physicist Stephen Wolfram, intelligent life is inevitable. But there is a hitch. Although intelligent life is inevitable, we will never find it -at least not by looking out in the Milky Way. As evidence Wolfram points out In order to compress more and more information into our communication signals - be they mobile phone conversations or computer- we remove all redundancy or pattern.
The Astrobiology Web. Extraterrestrial Life. The official U.S. government position on extraterrestrial life and the three major efforts to search for it. Clockwise from top left: NASA Astrobiology. Noogenesis.