[FPSPACE] FW: the physics arXiv blog - Can dark matter explain the flyby anomalies?

[LARRY KLAES]

>From: the physics arXiv blog <howdy at arxivblog.com>
>Reply-To: the physics arXiv blog <howdy at arxivblog.com>
>To: ljk4 at msn.com
>Subject: the physics arXiv blog
>Date: Wed, 21 May 2008 15:10:54 -0500 (CDT)
>
>the physics arXiv blog
>
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>Can dark matter explain the flyby anomalies?
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>Posted: 21 May 2008 04:37 AM CDT
>http://feeds.feedburner.com/~r/arXivblog/~3/294915302/
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>The flyby anomalies, you may remember, are a set of fascinating data 
>indicating that spacecraft flying past Earth undergo a strange, step-like 
>change in their acceleration.
>
>The Galileo, Near, Cassini and Rosetta spacecraft all seem to have been hit 
>by this weird phenomenon and while thats not a large number of data points, 
>it is an impressive proportion of the few spacecraft that have flown past 
>Earth on their way to other parts of the solar system.
>
>Nobody knows what causes this effect but there are a growing number of 
>fascinating ideas. For example, Ive blogged about a Casimir force-like 
>change in inertia. And today, Stephen Adler at the Institute for Advanced 
>Study in Princeton considers the possibility that these spacecraft are 
>banging into lumps of dark matter as they swing past the planet.
>
>In an impressive analysis, Adler doesnt rule out an interaction with dark 
>matter but he does impose some severe limits on how this process might 
>occur.  The problem is that weve witnessed both increases and decreases in 
>the acceleration of these spacecraft so any dark matter model would have to 
>allow for this.
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>Adler says that to fit the flyby data, the dark matter near Earth would 
>have to be much denser than in the rest of the solar system and many orders 
>of magnitude more dense than expected in our galaxy. It would have to be 
>confined to a Saturn-like ring around the Earth. And it would have to 
>consist of at least two types of dark matter.
>
>Of course thats possible but dark matter would have to be wildly more 
>complex than most scientists are willing to accept at the moment. So the 
>phenomenon remains a puzzle.
>
>Since I last blogged about this,  a  major peer-reviewed study from the Jet 
>Propulsion Laboratory has examined the data and pronounced the effect real. 
>   Which means that this is becoming one of the great outstanding 
>challenges in modern physics.  Expect to hear a lot more about it.
>
>Ref:  arxiv.org/abs/0805.2895: Can the Flyby Anomaly be Attributed to 
>Earth-bound Dark Matter?
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