So I have failed trying to watch every episode in a week so new goal: watch all of Cosmos this month!
This episode involved lots of comet stories.
“The Tunguska event, or Tunguska blast or Tunguska explosion, was an enormously powerful explosion that occurred near the Podkamennaya Tunguska River in what is now Krasnoyarsk Krai, Russia, at about 7:14 a.m. KRAT (0:14 UT) on June 30 [O.S. June 17], 1908.
The explosion is believed to have been caused by the air burst of a large meteoroid or comet fragment at an altitude of 5–10 kilometres (3–6 mi) above the Earth‘s surface. Different studies have yielded varying estimates of the object’s size, with general agreement that it was a few tens of metres across.”
And featured some comets in artwork, specifically Haley’s.
During the Apollo mission to the moon, the astronauts set up several mirrors on the surface of the moon. The McDonald Observatory near Ft. Davis, TX would shoot laser beams at those mirrors to measure the distance between the Earth and the moon with an accuracy of centimeters! They determined that the moon was indeed hit by a comet several centuries ago, as observed by some monks in Canterbury, England, based on the slight movement of the moon. http://mcdonaldobservatory.org/images/research/waad/d_mcd-1.jpg
The visible light spectrum was also used to determine the composition of the clouds above the surface of Venus.http://3.bp.blogspot.com/_nxSb3loAy3A/TGXoewM4W3I/AAAAAAAAAMA/GFb6edI3VTA/s1600/VisibleLightSpectrum2.jpg
Venus, our sister planet in terms of size, is covered in Carbon Dioxide clouds and is as hot as hell. The thick clouds increase the greenhouse effect on that planet, preventing the infrared waves from escaping its atmosphere and effectively warming the planet. A little greenhouse effect is a good thing, because without it on Earth, all of our water would be ice.