Friday, 26 August 2011
"Snow White" becomes for Caltech an embarrassingly Red dwarf-planet
Caltech astronomers are embarrassed about naming a KBO “Snow White”, now it has turned out to be one of the reddest objects in the solar system. Other large (~1000km) KBOs - ie. dwarf planets orbiting beyond Neptune and similar to Pluto - are also known to be red.
Though its spectrum shows water-ice, they now (22 August) rush to say the red-colour means a methane atmosphere. They are surely still misled by the paradigm that sees comets and icy moons as ice and snow, a fractured paradigm that still persists among some astronomers.
Outer solar system bodies like comets have been known tobe high in complex carbon compounds ever since the 1986 investigations of Halley’s comet. That showed Halley to be one of the darkest objects in the solar system, rather than an ice-ball. In 2005, the Deep Impact experiment on Tempel-1 showed a lot of fine organic-clay particles mixed with snow. Both showed methane is minor, if present at all.
Halley’s dark crust is doubtless produced via strongly heated of carbonaceous regolith by the Sun (at 0.6AU). The colour in the KBO objects is much more likely to arise via radiation processing of organics at the surface. However, radiation processing generally produces yellowish brown colours. Purer colours are in general chromophores as exist in biological pigments. The extended red emission of nebulae is a case in point. So the astronomers should be looking to identify the red-colour with chromophores - giving far more interesting implications!