Problems regarding the amount of oxygen in the solar system in comparison with space at large – see www.dailygalaxy.com/my_weblog/2013/06/did-our-solar-system-evolve-in-a-m…
At www.space.com/21758-comet-ison-summer-brightness.html … the size of this comet is still open to dispute but is currently obscured from view as it approaches the Sun