And I just want to end on this note: not long after comet ISON was discovered, it began to raise questions. Throughout this year, as many of you who have followed closely will appreciate, it has continued to confuse and surprise us. For the past few weeks, it has been particularly enigmatic and dynamic, in addition to being visually spectacular. This morning we thought it was dying, and hope was lost as it faded from sight. But like an icy phoenix, it has risen from the solar corona and - for a time at least - shines once more. This has unquestionably been the most extraordinary comet that Matthew and I, and likely many other astronomers, have ever witnessed. The universe is an amazing place and it has just amazed us again. This story isn't over yet, so don't stray too far from your computer for the next couple of days!