Astrobiology and SETI

A New Context for Complex Life

January 18, 2017

We normally think of the appearance of oxygen on Earth in terms of a ‘great oxygenation event,’ sometimes referred to as the ‘oxygen catastrophe’ or ‘great oxidation.’ Here oxygen begins to emerge in the atmosphere about 2.3 billion years ago as oceanic cyanobacteria produce oxygen by photosynthesis. The actual oxygenation event would be the point […]

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Inconstant Moons: A New Lunar Origin Scenario

January 13, 2017

A recent snowfall followed by warming temperatures produced a foggy night recently, one in which I was out for my usual walk and noticed a beautiful Moon trying to break through the fog layers. The scene was silvery, almost surreal, the kind of thing my wife would write a poem about. For my part, I […]

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Citizen SETI

December 21, 2016

I love watching people who have a passion for science constructing projects in ways that benefit the community. I once dabbled in radio astronomy through the Society of Amateur Radio Astronomers, and I could also point to the SETI League, with 1500 members on all seven continents engaged in one way or another with local […]

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Freelancing an Interstellar Message

November 28, 2016

The problem in sending intentional signals to the stars isn’t technology. It’s our lack of consensus. Having widespread buy-in on whether, why and how to add an ‘active’ component to SETI is deeply polarizing, at least on the surface. But dig deeper: While there are those who think we should send signals about ourselves to […]

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Looking for ‘Technosignatures’

November 22, 2016

We speculated yesterday that categorizing civilizations on the basis of their power use may not be a given, though it is the basis of the familiar Kardashev types. It seems natural to a rapidly changing technological society like ours that the trend is always upward, a clear path toward harnessing the energies of the home […]

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SETI in the Anthropocene

November 21, 2016

Have we, as some have argued, entered a new ‘age of humanity,’ the so-called Anthropocene? The notion is controversial in many quarters, but it addresses the growing concern about our human influence on the Earth and the nature of planetary change. David Grinspoon’s new book Earth in Human Hands (Grand Central Publishing, 2016) has much […]

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Proxima Centauri Observations Launch Parkes Effort

November 9, 2016

In the last two days we’ve looked at a discussion of a possible SETI observable, a ‘shielding swarm’ that an advanced civilization might deploy in the event of a nearby supernova. As with Richard Carrigan’s pioneering searches for Dyson swarms in the infrared, this kind of SETI makes fundamentally different assumptions than the SETI we’ve […]

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‘Shielding Swarms’ & SETI Observables

November 8, 2016

If you’re on the Moon and learn that there has been a major solar eruption, your best course of action is to get inside an appropriate shelter somewhere below ground, where you can be shielded from its effects. By analogy, wouldn’t a future civilization on Earth be able to shield itself from the effects of […]

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Risk Mitigation for Advanced Civilizations

November 7, 2016

Alastair Reynolds’ 2008 novel House of Suns contains what must be the most outrageous solution for an endangered civilization I’ve ever encountered. Set some 6 million years in the future, the story involves technologies at the Kardashev Type III level — in other words, civilizations that are capable of harnessing the energy of entire galaxies. […]

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A Renewed Look at Boyajian’s Star

October 27, 2016

It was inevitable that KIC 8462852 would spawn a nickname, given the public attention given to this mystifying star, whose unusual lightcurves continue to challenge us. ‘Tabby’s Star’ is the moniker I’ve seen most frequently, but we now seem to be settling in on ‘Boyajian’s Star.’ It was Tabetha Boyajian (Louisiana State) whose work with […]

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