September 2006

Active SETI Redux

September 30, 2006

The thread on active SETI — broadcasting messages from Earth in a targeted way to other star systems — has been an active and fruitful one. Unfortunately, I’m getting a few reports that recent attempts to post new comments haven’t been successful. This may involve a size limit on comments to a single post; in […]

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A Vast Protoplanetary Disk

September 29, 2006

The disks of gas, dust and debris that surround young stars are breeding grounds for planets, a premise that every new exoplanet detection seems to confirm. But we know little about the disks themselves, and a key area of uncertainty continues to be the nature of disks around stars more massive than the Sun. What […]

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Two Transiting Hot Jupiters Found

September 28, 2006

The transit method has now bagged its 13th and 14th planets, both of them ‘hot Jupiters’ so close to their stars that their orbits are two and two and one-half days respectively. That makes for temperatures well over 1800 degrees Celsius, and adds more data points in our improbable collection of massive planets that all […]

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Antimatter’s Oscillations Probed

September 27, 2006

An operating run at Fermilab involving the Tevatron, the world’s highest-energy particle accelerator, has produced an experimental result of extraordinary precision, one that has measured transitions between matter and antimatter that occur three trillion times a second. Tevatron Run 2, from February of 2002 to January of this year, produced trillions of collisions between protons […]

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Should SETI Turn Active?

September 26, 2006

Centauri Dreams admits to troubling new doubts about a variant of SETI called METI — Messaging to Extraterrestrial Intelligence. The notion, also known as ‘active SETI,’ is backed by some members of the SETI community and is especially strong in Russia. Its premise is that rather than listening passively for signs of extraterrestrials, we should […]

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A Dream of Ancient Starlight

September 25, 2006

There are images that need to be appreciated slowly, the way you sip a rare wine. They should be carried with you a while, pondered, mulled over, and sometimes, as happened to me last night, they slip into your dreams. That dream was powerful enough to push the image below into today’s entry. It’s a […]

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Looking Back at Orion

September 23, 2006

Whenever I think about Project Orion, I recall the ‘putt-putt’ experiments that tested the propulsion concept back in 1959. It was hardly an atomic spaceship, but the little putt-putt called ‘Hot Rod’ is as far as Orion ever got operationally. Using chemical explosives, Hot Rod rose 100 meters, a brief flight that nonetheless validated the […]

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Saturn’s Rings in a New Light

September 22, 2006

The imagery from Cassini’s twelve-hour pass behind Saturn turns out to have been productive indeed. We pause from things interstellar, then, to admire the beautiful photograph below. The occultation of the Sun put the spacecraft in position to see the rings with exquisite and detail-enhancing backlighting, providing striking visual evidence for their extensive interaction with […]

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Brown Dwarf Discoveries Multiply

September 21, 2006

Brown dwarfs are clearly commonplace in the galaxy, but we know all too little about them. Thus the excitement about the recent imaging of a brown dwarf that orbits its star along with a planet. More information about that dwarf, HD 3651 B, has now surfaced thanks to a preprint passed along by Massimo Marengo […]

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A Further Look at Galactic Catastrophism

September 20, 2006

Galactic catastrophism — the idea that certain kinds of cosmic events can destroy life on a periodic basis and prevent the emergence of technological civilizations — comes in a number of variants. And some catastrophe theorists believe such events don’t necessarily rule out species survival because their effects change over time. As we saw yesterday, […]

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