= Cometary coma
A <cometary coma> is the extended cloud of <gas> and dust surrounding an active <comet nucleus>. Released material expands away from the nucleus and is altered by sunlight, chemistry and interactions with the solar environment.
Different <spectral lines> can trace different <molecules> or their dissociation products, while dust scatters sunlight and emits thermally. The resulting image combines source activity, transport and excitation. It is therefore a physical environment around the nucleus rather than a solid extension of its surface.
Back to article page
