http://news.nationalgeographic.com/news/2012/04/120419-dark-matter-sun-m... "In the new study, Moni-Bidin and his colleagues used the European Southern Observatory's La Silla and Las Campanas telescopes in Chile to map the three-dimensional motions of more than 400 red giant stars up to 13,000 light-years from the sun. Stars in the sky may appear static, but they're constantly in motion as they get minutely pushed and pulled by the gravitational effects of neighboring objects, including other stars, gas clouds, or clumps of dark matter. The team compared their measurements of stellar motion with what they predicted the motions would be if the stars' movements were affected by visible matter alone. To their surprise, the two sets of measurements matched. In other words, dark matter was not necessary to explain the motions of the sun and its close neighbors. "These observations point to the fact that in this volume [of space], there is no dark matter," Moni-Bidin said." Coverage of the issue, there and elsewhere, suggests that the question remains open, that the definitive non-existence of dark matter in the solar neighbourhood isn't even disproved by the evidence so far. It makes you think, no?