Directory enquiries <a href=" http://www.splodar.ie/index.php/dostinex-05-mg-pret.pdf#steadily ">dostinex quanto costa in farmacia</a> Some comets develop extensive tails, which can be many tens of millions of miles long. Also, as the comet gets closer to the Sun it will usually brighten very rapidly. If this is the comet&rsquo;s first encounter the Sun, it most likely has a lot of loose material on the surface and much fresher subsurface material that will react to the solar heat, which will be blown off by the solar wind creating a large and bright coma, as well as a lengthy tail. An old comet that has made many trips through the inner solar system may have exhausted a lot of this material and any activity may be minimal. Eventually most of the volatile material contained in a comet nucleus evaporates away and the comet &ldquo;dies out.&rdquo;