September 2007

Notes & Queries 9/29/07

September 29, 2007

Franklin Chang-Diaz, astronaut and CEO of Ad Astra Rocket Company, intends to test the VX-200 VASIMIR prototype in January. VASIMIR (Variable Specific Impulse Magnetoplasma Rocket) offers much greater fuel efficiency than conventional chemical rockets, working with hot plasma heated by radio waves and controlled by a magnetic field. Technology Review talks to Chang-Diaz about the […]

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Ion Propulsion Flies Again — When Will Sails?

September 28, 2007

The launch of the Dawn mission to the asteroids makes me think about solar sails. I realize that Dawn uses ion propulsion, about which more in a moment, but watching ion methods as they mature makes an emphatic point: We need to bring solar sail technologies up to the same readiness level that ion propulsion […]

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Radio Burst Flags Celestial Oddity

September 27, 2007

An odd radio burst that seems to signal a previously undiscovered astrophysical phenomenon is now on the scene. Culled out of archival data gathered from the Parkes radio telescope in Australia, the burst may signal something exotic indeed, the last stages of the evaporation of a black hole. Another candidate: A collision between two neutron […]

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Dawn Mission Launched to Asteroids

September 27, 2007

Great to see Dawn on its way. The spacecraft lifted off at 11:34 UTC, with signal acquisition just over one hour into the flight. The spacecraft will begin its exploration of Vesta in 2011 and Ceres in 2015, two asteroids that between them have much to tell us about the history of the Solar System. […]

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Planets of Iron, Planets of Ice

September 26, 2007

How large a planet is depends upon its composition and mass. Earth is largely made of silicates, with a diameter of 7,926 miles at the equator. Imagine an Earth mass planet made of iron and you’re looking at a diameter of a scant 3000 miles. Interestingly, the relationship between mass and diameter follows a similar […]

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Exploring the Submillimeter Universe

September 25, 2007

By Larry Klaes Tau Zero journalist Larry Klaes here offers a look at a revolutionary telescope that will soon take our vision of the universe into new domains. In the early half of the next decade, an instrument called the Cornell Caltech Atacama Telescope (CCAT) is planned to examine the Universe through a less-studied region […]

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Habitable Planets: A Splendid Isolation?

September 24, 2007

Our assumptions about terrestrial planets seem pretty straightforward. We’re only now reaching the level where detecting such worlds becomes a possibility, with advances in ground- and space-based telescopes imminent that will begin to give us an idea how common such planets are. Hoping for the best, we assume Earth-sized worlds in relatively comfortable places are […]

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Notes & Queries 9/22/07

September 22, 2007

Apropos of our recent speculations about planets without stars, this short podcast from Earth & Sky discusses dark planets within our galaxy able to sustain life, at least for a while. The scenario, developed by John Debes (Carnegie Institution) and Steinn Sigurðsson (Pennsylvania State): A planet with a large moon passes near a giant world […]

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The View from an Intergalactic Straggler

September 21, 2007

Speaking of absorbing views from a planetary surface, as we’ve been doing recently when discussing the Magellanic Clouds and what an observer there might see of the Milky Way, consider a much darker scenario. A galaxy called ESO 137-001 is in headlong flight toward the center of the galactic cluster Abell 3627. It is leaving […]

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Tau Ceti: Life Amidst Catastrophe?

September 20, 2007

Tau Ceti has always been an interesting star, one of two (the other being Epsilon Eridani) that Frank Drake chose as targets for his pioneering Project Ozma SETI observations. The astrobiological interest is understandable. We’re dealing with a Sun-like star relatively close (11.9 light years) to Earth. But recent thinking downplays Tau Ceti as a […]

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