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TOPIC: Alien life
Blobrana


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Extraterrestrial life
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Title: Finding extraterrestrial life using ground-based high-resolution spectroscopy
Authors: Ignas Snellen, Remco de Kok, Rudolf Le Poole, Matteo Brogi, Jayne Birkby

Exoplanet observations promise one day to unveil the presence of extraterrestrial life. Atmospheric compounds in strong chemical disequilibrium would point to large-scale biological activity just as oxygen and methane do in the Earth's atmosphere. The cancellation of both the Terrestrial Planet Finder and Darwin missions means that it is unlikely that a dedicated space telescope to search for biomarker gases in exoplanet atmospheres will be launched within the next 25 years. Here we show that ground-based telescopes provide a strong alternative for finding biomarkers in exoplanet atmospheres through transit observations. Recent results on hot Jupiters show the enormous potential of high-dispersion spectroscopy to separate the extraterrestrial and telluric signals making use of the Doppler shift of the planet. The transmission signal of oxygen from an Earth-twin orbiting a small red dwarf star is only a factor 3 smaller than that of carbon monoxide recently detected in the hot Jupiter tau Bootis b, albeit such a star will be orders of magnitude fainter. We show that if Earth-like planets are common, the planned extremely large telescopes can detect oxygen within a few dozen transits. Ultimately, large arrays of dedicated flux collector telescopes equipped with high-dispersion spectrographs can provide the large collecting area needed to perform a statistical study of life-bearing planets in the solar neighbourhood.

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Blobrana


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RE: Alien life
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ET would find Earth boring, says Sir Patrick Moore

Evidence of planets supporting alien life beyond the solar system will be found within the next 50 years, renowned astronomer Sir Patrick Moore has predicted. But those fearing unwelcome visits can rest easy - he says Earth is too 'boring' for extra-terrestrials to bother with.
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Blobrana


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Former UFO adviser says Britain is totally ready for alien war

Lord Martin Rees, personal astronomer to Queen Elizabeth II, is certain we'll encounter alien life in the next 40 years. And Nick Pope, who worked as UFO adviser for the Ministry of Defence for 21 years, says we're ready to smoke 'em if they're aren't polite.
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Blobrana


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Aliens in the oceans -- searching for life on the moons of Jupiter

Along with continuing our exploration of Mars there are several moons of Jupiter and Saturn that we think might be good places for life.
These moons -- worlds with names like Europa, Enceladus, and Titan -- are covered with solid water ice, beneath which we have very good reason to believe that vast liquid water oceans exist.
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Blobrana


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Could there be life on five newly discovered planets?

Is life on other planets possible? Well a team of American astronomers certainly seem to think so.
Five new planets were discovered by NASA's Kepler Space Telescope earlier this year and even though they're 10,000 light-years away from us, we have a lot in common.
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Blobrana


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Title: Can Ground-based Telescopes Detect The Oxygen 1.27 Micron Absorption Feature as a Biomarker in Exoplanets ?
Authors: Hajime Kawahara, Taro Matsuo, Michihiro Takami, Yuka Fujii, Takayuki Kotani, Naoshi Murakami, Motohide Tamura, Olivier Guyon

The oxygen absorption line imprinted in the scattered light from the Earth-like planets has been considered as the most promising metabolic biomarker of the exo-life. We examine the feasibility of the detection of the oxygen 1.27 micron band from habitable exoplanets, in particular, around late-type stars with a 30 m class ground-based telescope with a future instrument. We analysed the night airglow around 1.27 micron with IRCS/echelle spectrometer on Subaru and found that the strong telluric emission from atmospheric oxygen molecules declines by an order of magnitude by the midnight. With compilation of nearby star catalogues combined with the sky background model, we estimate the detectability of the oxygen absorption band from an Earth twin, if exists, around nearby stars. We find that the most dominant photon noise of the oxygen 1.27 micron detection comes from the night airglow if the leakage is suppressed enough to detect the planet. We conclude that the future detectors for which the detection contrast is limited by photon noise can detect the oxygen 1.27 micron absorption band of the Earth twins for \sim 100 candidates of the late type star. This paper demonstrates the importance of deploying small inner working angle efficient coronagraph and extreme adaptive optics on extremely large telescopes, and clearly shows that doing so will enable study of potentially habitable planets.

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Title: From Cosmos to Intelligent Life: The Four Ages of Astrobiology
Authors: Marcelo Gleiser

The history of life on Earth and in other potential life-bearing planetary platforms is deeply linked to the history of the universe. Since life as we know it relies on chemical elements forged in dying heavy stars, the universe needs to be old enough for stars to form and evolve. Current cosmological theory indicates that the universe is 13.7±0.13 billion years old and that the first stars formed hundreds of millions of years after the big bang. At least some stars formed with stable planetary systems wherein a set of biochemical reactions leading to life could have taken place. In this lecture, I argue that we can divide cosmological history into four ages, from the big bang to intelligent life. The Physical Age describes the origin of the universe, of matter, of cosmic nucleosynthesis, as well as the formation of the first stars and galaxies. The Chemical Age begun when heavy stars provided the raw ingredients for life through stellar nucleosynthesis and describes how heavier chemical elements collected in nascent planets and moons to give rise to prebiotic biomolecules. The Biological Age describes the origin of early life, its evolution through Darwinian natural selection, and the emergence of complex multicellular life forms. Finally, the Cognitive Age describes how complex life evolved into intelligent life capable of self-awareness and of developing technology through the directed manipulation of energy and materials. We conclude discussing whether we are the rule or the exception.

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Blobrana


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Fermi Paradox
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Are we alone in the universe?

As the romance of manned space exploration has waned, the drive today is to find our living, thinking counterparts in the universe. For all the excitement, however, the search betrays a profound melancholy - a lonely species in a merciless universe anxiously awaits an answering voice amid utter silence.
That silence is maddening. Not just because it compounds our feeling of cosmic isolation, but because it makes no sense. As we inevitably find more and more exo-planets where intelligent life can exist, why have we found no evidence - no signals, no radio waves - that intelligent life does exist?
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Blobrana


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RE: Alien life
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Wernicke: Is there anyone out there?

Are we alone?

For space exploration, that is THE great question. It is one of the fundamental questions for all mankind, an existential query that could answer - or create - basic questions about the fundamental nature of existence.
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Blobrana


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Astrobiology
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Harvard Professors Search for Alien Life
 
Discovering extraterrestrial life is not a new goal on mankind's to-do list.
The search, of course, has traditionally played a larger role in popular culture than in the halls of academia.
But over the last 40 years, the question of whether we are alone in the universe has formed a new field in the sciences. Astrobiology, the study of life in space, is no longer relegated to the stuff of science fiction and alien enthusiasts.
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