Can dark matter explain the flyby anomalies?

Flyby anomaly

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 that’s 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, I’ve 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 doesn’t rule out an interaction with dark matter but he does impose some severe limits on how this process might occur. The problem is that we’ve witnessed both increases and decreases in the acceleration of these spacecraft so any dark matter model would have to allow for this.

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 that’s 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?

5 Responses to “Can dark matter explain the flyby anomalies?”

  1. KFC says:

    Thanks TLP, but the Pioneer anomaly is a different effect.

  2. Roger Ellman says:

    The “flyby anomalies” are caused by the same action that causes the “pioneer anomaly” and the shape of galactic rotation curves that caused dark matter to be inferred: the exponential decay of the length dimension of the universe and of all its contents, which produces the effect of a small acceleration “inward” all as presented in full detail in arXiv physics/9906031 and broadly in physics/9808051. That decay accounts for the above effects plus the Type SN1A supernovae data that resulted in the dark energy hypothesis, and that decay is the principal cause of red shifts, recession velocities being actually much smaller than the unreasonably large values presently accepted and doppler shift being only a minor part of redshifts.

  3. Qasem says:

    The paradigm of dark matter seemed ostensible at the beginning. However, now, as more effects are attributed to the hypothetical presence of dark matter further assumptions must be presumed on how many kind of dark matters we have, what strange interactions they possess and etc..

    For me, as an outside observer, the dark matter paradigm is not fascinating anymore. I evaluate this paradigm as the new terra incognito!

  4. omni-impotent says:

    dark matter concentrated around Earth with intelligent lifeforms… sounds more & more like His Dark Materials series (i.e. the Golden Compass). :)