Pictorial view of the Earth's orbit and the interstellar flow, as seen from far above the North Pole. During the wind's journey through the Sun's gravitation, it is bent like a soccer ball that is pulled back to Earth in a curve. Slower wind (dark blue) is bent stronger than faster wind. Thus, during the month of February, when the Earth moves into the interstellar flow, the Interstellar Boundary Explorer (IBEX) observes slower wind earlier on Earth's orbit than faster wind. To determine the flow speed, the IBEX team has taken advantage of this "speedometer" that Mother Nature freely provides. This image relates to a paper that appeared in the 6 September, 2013, issue of Science, published by AAAS. The paper, by Priscilla Frisch at University of Chicago in Chicago, IL, and colleagues was titled, "Decades-Long Changes of the Interstellar Wind Through Our Solar System."