XingCai Tang's Original Blog
The planet Mercury reflects much less light compared to our own moon, which is about the same size. This had scientist bewildered for a long time. Scientists at Lawrence Livermore National Laboratory, Brown University and the Planetary Sciences Institute say they may have found the solution. Megan Bruck Syal, a postdoctoral researcher at Lawrence Livermore, said that it was "effectively painted black".
Mercury is the planet that is closest to the sun. Compared to the moon, there is are much more carbon dust flung off from comets close to the sun. The researchers say Mercury is surrounded by 50 times the amount of carbon dust than our moon. For ages scientist believes that microscopic meteorites spawned from carbon-rich comets may have contributed enough dark-hued carbon to reduce the amount of reflected light.
Tests using a big NASA gun made to simulate planetary impacts on a small-scale seem to show the theory is plausible, the authors say. "We show that carbon acts like a stealth darkening agent," said Peter Schultz, a professor emeritus of geological sciences at Brown University. "From the standpoint of spectral analysis, it's like an invisible paint," the CNN reported on 31 March 2015.
My Comments
The microscopic meteorites spawned from carbon-rich comets are like blots of black ink waiting to drop on Mercury.
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