Brown Dwarf With Water Clouds Tentatively Detected Just 7 Light-Years From Earth 85
sciencehabit (1205606) writes Astronomers have found signs of water ice clouds on an object just 7.3 light-years from Earth — less than twice the distance of Alpha Centauri. If confirmed, the discovery is the first sighting of water clouds beyond our solar system. The clouds shroud a Jupiter-sized object known as a brown dwarf and should yield insight into the nature of cool giant planets orbiting other suns.
Re:Is this the missing "dark matter"? (Score:5, Informative)
No, the amount of missing matter is far to great to be contained in such small objects even if they were incredibly numerous.
Consider the entire mass of the asteroid belt is estimated to be only 4% of the Moon's mass, and the Moon's mass is only 1/81 of the Earth's.
Dark matter, meanwhile, is thought to have a total mass more than 5 times greater than that of normal matter.
Re:Is this the missing "dark matter"? (Score:2, Informative)
Logic fail. Dark matter can be explained by such small objects if they are incredibly numerous. It's just math: divide the missing mass by the mass of one brown dwarf to get the number needed. If you want to disprove the brown dwarf explanation you need to explain why the number that is needed contradicts something.
Re:Is this the missing "dark matter"? (Score:5, Informative)
Its not a simple argument but if you look at:
http://en.wikipedia.org/wiki/D... [wikipedia.org]
dark matter composed of bits of normal baryonic matter is not consistent with observations / simulations
Re:Moons? (Score:4, Informative)
Indeed it does. I haven't published yet, but I detected one a few days ago (I work out of a valley in Iceland). I observed the brown dwarf in question (right ascension 08h 55m 10.83s, declination -07 14 42.5") and detected a large, earth-sized body occluding the star during my brief observations.