Summary and Discussion:
The Pioneer 10 and Pioneer 11 spacecrafts have been experiencing unexplainable changes in their movement. Lodged deep in space at the edge of the solar system, their acceleration, the rate at which velocity changes, is decreasing, due to an unclear force. Originally thought to have been the cause of the sun's gravity, physicists have shown in 1998 that this could not have been the case. Although the deceleration is tiny, only -8.74 x 10^-10 meters per second squared, scientists believe that the only "force" that could have caused it is heat. In some cases, the emission of energy from the spacecraft slows it down, and at other times, the spacecraft's reflection of infrared rays, or heat waves, from various sources causes the deceleration. Orfeu Bertolami designed a computer model which calculated the effects of the heat, which turned out to be reasonably close to the actual deceleration of the spacecraft. However, 13 years ago, John Anderson, a retired NASA Scientist, stated that the heat effects could not have accounted for the deceleration. Although many scientists have many theories and ideas, it is still unclear what the cause of this mysterious acceleration decrease is. I chose this article to write about because I am interested in physics and outer space. It is interesting to find out what is causing this abnormal motion. In the future, after discovering what is the true cause of the deceleration, scientists may be able to take advantage of this idea and apply it to new scientific inventions. However, if no reasonable cause is identified, scientists can send out a new spacecraft that closely observes the effects of heat on the motion of the spacecraft. Overall, I thought that this article provided me with some insight on the problems scientists face and how they attempt to solve them.
Resources:
Cowen, Ron. "Pioneer puzzle pinned on thermodynamics." Science News 7 Apr. 2011:
n. pag. Science News. Web. 7 Apr. 2011. <http://www.sciencenews.org/view/
generic/id/72392/title/Pioneer_puzzle_pinned_on_thermodynamics>.
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