Washington: NASA`s Interstellar Boundary Explorer (IBEX) spacecraft`s data has revealed that neutral interstellar atoms are flowing into the solar system from a different direction than had previously been observed.
Interstellar atoms flow past the Earth as the solar system passes through the surrounding interstellar cloud at 23 kilometers per second (50,000 miles per hour).
The latest IBEX measurements of the interstellar wind direction were discovered to differ from those made by the Ulysses spacecraft in the 1990s.
That difference led the IBEX team to compare the IBEX measurements to data gathered by 11 spacecraft between 1972 and 2011. Statistical testing of the Earth-orbiting and interplanetary spacecraft data showed that, over the past 40 years, the longitude of the interstellar helium wind has changed by 9.2 - 4.4 degree range.
Dr. Priscilla Frisch, lead author of the study and a senior scientist in the Department of Astronomy and Astrophysics at the University of Chicago, said that they concluded it`s highly likely that the direction of the interstellar wind has changed over the past 40 years.
She said that it`s also highly unlikely that the direction of the interstellar helium wind has remained constant.
Frisch added that they believe that the change in wind direction could be explained by turbulence in the interstellar cloud around the Sun.