The old tail receded farther downstream until it dissipated completely, while the part that remained lengthened to form the new gas tail.
North is to the upper left.
He assembled these mosaics from individual exposures lasting 2.5 to 3 minutes. Note the changing size of the comet's head as it approached and receded from Earth. Mizar and Alcor, forming a bright double star, appear in the middle frame. Its unusually close flyby to Earth gave millions of people an opportunity to see the finest comet in 20 years. A fortuitous series of events is all that stands between visibility and anonymity for these shells cast off by dying stars.