Dark Matter

The Horse Head nebula in Orion gets its shape from dark unilluminated gas silhouetting a bright illuminated part of the nebula. Clearly, if no stars are near a particular nebula it can not shine. But ‘Dark Matter’ is more than simply an unilluminated blob of gas.

If the dynamics of a galaxy of stars is studied, it is found that a certain mass is required to hold the system together. However, the sum total of all the mass of stars is below this critical mass. Moreover, the estimated amount of unilluminated gas and dust is insufficient to make up the shortfall.

The missing mass to hold the galaxy together is called ‘Dark Matter’ and investigations are ongoing as to the nature of this mysterious matter.

New Scientist 23 March 2006 : An as-yet undetected type of neutrino could explain a host of astrophysical conundrums, from the nature of dark matter to the ignition of the first stars, a new study suggests. But verifying the particle's existence could prove difficult.

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