Scientists are puzzled by unexpected
acceleration in several unmanned
spacecraft as they flew toward the
previous Thunderbolts Picture of the Day article about the so-called
“Pioneer anomaly”, we noted that NASA scientists have determined that both
Pioneer 10 and 11 are off course by more than a hundred thousand kilometers.
Mission specialists admitted that they had no explanation for the navigational
deviation so many speculations were announced to the press about what
“mysterious” forces could be acting on the tiny probes.
As long ago as
September 1998, however, the same enigmatic forces were also reported to be
acting on the Ulysses spacecraft that is currently in a high orbit through the
Solar System. In that case Ulysses demonstrated a sunward acceleration when
radio signals from Earth bounced off a transponder onboard the solar observatory
and indicated a Doppler shift in the frequency of the return transmission. The
induced frequency shift was greater than could be affected by any known
mechanism and no one in the conventional science community can yet account for
More space probes are now being added to the mix. After examining telemetry from
NEAR-Shoemaker (now resting on the surface of Asteroid Eros), the Galileo
mission to Jupiter, Cassini-Huygens (one part each orbiting Saturn and the other
resting on the surface of Titan), the
cometary probe and the MESSENGER mission to Mercury, a similar discrepancy
has been detected.
John Anderson, a retired astronomer currently on assignment to NASA,
"I am feeling both humble and perplexed by this. There is something very strange
going on with spacecraft motions. We have no convincing explanation for either
the Pioneer anomaly or the flyby anomaly.... We should continue to monitor
spacecraft during Earth flybys. We should look carefully at newly recovered
Pioneer data for more evidence of the Pioneer anomaly. We should think about
launching a dedicated mission on an escape trajectory from the solar system,
just to look for anomalies in its motion."
Astronomers are baffled by this situation because the standard theories of
motion in the cosmos rest within a gravitational model. In fact, gravitational
theory is considered by cosmologists to be the most useful way of explaining the
way that the universe behaves, as well as being one of its
Modified Newtonian Dynamics (MOND) is one of the more exotic ideas proposed for
how the spacecraft are being affected by these subtle changes in speed and
direction. Perhaps it is no more exotic than suggesting multi-dimensional space,
dark energy, dark matter friction and other non-falsifiable theories like
“gravity affecting anti-matter differently.”
This is yet another in a long line of speculative ideas that must be concocted
when no thought is given to the positive charge that resides in the Sun. The
Sun’s positive charge sets up a steady electric field in the plasma of
interplanetary space that attracts negatively charged objects back towards it.
In another Thunderbolts Picture of the Day, we discussed “backstreaming
electrons” as evidence for the Sun’s electric field.
When spacecraft are launched into Earth orbit, or out to explore the other
planets, they gather a
as fast-moving electrons build up on the surface. Typically the shell of a
satellite can gain hundreds or thousands of volts relative to its plasma
As Wal Thornhill discussed in
Mystery Solved," in the weak but steady electric field
of the Sun negatively charged spacecraft will experience a
small “anomalous” acceleration toward the Sun. Scientists
seem much too eager to invoke "new physics" when the first
requirement is to choose the right model. Then the "old"
physics will do. Perhaps today "new physics" has too much
appeal in the frantic scramble for a Nobel Prize.