This is CBS. I am the World Hotel Mars episode N. I'm John Bachelor, my colleague and co-host and co-pilot David Livingston, Dr Space Himself of the Space Show.

And we're very pleased to welcome the Senior Scientist for Astrobiology Strategy at

NASA, David Grinsboon, the author of several books, the one that I am particularly keen on.

It was early days when he wrote about all the planets and their possibilities for astrobiology and that is still a wonderful treat

right now however we're going to turn to the magic of the skies it is a moment to celebrate.

Holly's Comet, which is in history, burned in history of the last 2,000 years, from associated with the Bible, with the rising of the Jews against the Romans in 1st century

AD all the way to the appearance in 1910 when it was feared that the tale of

Holly's comment would spread poison gas on the earth and we're all going to die.

Holly's common is coming back. on the earth and we're all going to die.

Holly's common is coming back.

It's reached its aphelion outside Neptune, 3 billion miles I believe, roughly give or take

a hundred thousand. And it's headed back to earth every

76 years or so it comes and it comes with history so we welcome David Grinspoon to

comment on Holly's comment because Holly's comment was one of the ways

early science Holly himself managed to calculate in order to justify or at least

back up their early understanding of the universe and of

location on Earth.

It was extremely important because it's a moving object.

It's not a fixed planet.

David Grinspoon, Dr Grinspoon, a very good evening to you.

Do you have a photograph up of Holly's comment at NASA

anywhere in the corridor?

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