October 2005

On Deflecting Near Earth Objects

October 31, 2005

The B612 Foundation continues to examine the danger of near-Earth objects (NEOs). As noted earlier in these pages, B612 points to the continuing evidence for asteroid and comet impacts and their role in shaping the planet’s history; the much discussed demise of the dinosaurs, due to a likely asteroid strike in the Yucatan, is but […]

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Robert Goddard on Interstellar Migration

October 29, 2005

“A manuscript I wrote on January 14, 1918 … and deposited in a friend’s safe … speculated as to the last migration of the human race, as consisting of a number of expeditions sent out into the regions of thickly distributed stars, taking in a condensed form all the knowledge of the race, using either […]

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Photon Pressure Affects Japanese Spacecraft

October 28, 2005

The Japanese spacecraft Hayabusa, now in a ‘parking orbit’ above the asteroid Itokawa, is providing good evidence of just how useful the pressure of solar photons can be. Japan’s Institute of Space and Aeronautical Science (ISAS) reports that the force being experienced by the spacecraft is 1/100th of the thrust produced by its ion engines, […]

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A Gravitational Lens at Work

October 27, 2005

Gravitational lenses of the sort discussed in yesterday’s post are now widely discussed. The idea that gravity can bend light may seem counterintuitive but we’ve seen numerous demonstrations of the effect, starting with the famous eclipse studied by Arthur Eddington in 1919. Hoping to test Einstein’s general theory of relativity, Eddington traveled to the island […]

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A Mission to the Gravity Focus

October 26, 2005

Voyager 1 is, in a sense, our first interstellar spacecraft, with evidence mounting that it has reached the heliopause, that area marking the boundary between the Sun’s outward-flowing particles and the true interstellar medium. The New Horizons mission, scheduled for launch in January, will go on to explore at least part of the Kuiper Belt. […]

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Deep Space Transmission Strategies

October 25, 2005

One reason we need to re-think our communications strategies is that our resources are so limited. The Interplanetary Internet Project, for example, points out as a major justification for its work that if we can network spacecraft in distant planetary environments, we can sharply cut back on the amount of antenna time needed. After all, […]

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The Best Way to View Terrestrial Worlds

October 24, 2005

Centauri Dreams has been a champion of Webster Cash’s New Worlds Imager for several years now. The proposal, whose initial study was funded by NASA’s Institute for Advanced Concepts, offered a way to find terrestrial planets around other stars and, in its most fully developed configuration, to create startlingly sharp images of such worlds down […]

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Brown Dwarfs May Have Planets

October 22, 2005

If brown dwarfs, those ‘failed stars’ that never make it to the stage of full nuclear burning, can have planets around them, then the speculations of Karl Schroeder’s novel Permanence (New York: Tor Books, 2002) may be closer to reality than Centauri Dreams once thought. Schroeder imagines human colonies, artificially sustained through extraordinary technologies, on […]

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SETI and Drake: Part II

October 21, 2005

Yesterday we looked at Milan Ćirković’s paper “The Temporal Aspect of the Drake Equation and SETI” (Astrobiology Vol. 4 No. 2, pp. 225-231), and pondered whether there might not be a ‘communications window’ — an interval for any society between when it reaches the technological capacity for interstellar communication and the point when it becomes […]

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A Hard Look at SETI and the Drake Equation

October 20, 2005

The famous Drake Equation was developed as a way to estimate how many technological civilizations might exist and thereby be targets for SETI research. Conceived in 1961 as astronomer Frank Drake worked at the National Radio Astronomy Observatory (Green Bank, WV), the equation exists in a variety of forms depending on which authors you consult […]

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