Standing Up In The Milky Way Facts
Comets, Clouds, and Carl Sagan
Our Milky Way galaxy, spanning a length of 100,000 light-years, constantly rotates—our solar system moves through it at speeds over 450,000 miles per hour.
Our solar system’s hottest planet is Venus, the planet’s high levels of atmospheric carbon dioxide creating a greenhouse effect that renders the planet’s surface hotter than its neighbor Mercury, technically the closer planet to the sun.
On the outskirts of the solar system exists the Oort Cloud, a cluster of billions of frozen comets. In 1950, Dutch astronomer Jan Oort proposed the existence of comets that originate from this vast shell of icy bodies, giving the cloud its namesake.
Comets occasionally fall from the Oort Cloud into the inner region orbit of our solar system, dislodged by nearby stars or molecular clouds. Called long-period comets, these bodies are very rare, taking thousands of years to circle the sun due to their the large size of their orbits.
Giordano Bruno was born in 1548 in Nola, an Italian town near Naples. His birth given name was Filippo but he changed it to Giordano upon entering a Dominican Monastery in Naples where he was taught philosophy. From there his strong beliefs took him to many cities including Rome, Paris, London, Oxford, Wittenberg, Prague, Helmstedt, Frankfurt, and Venice.
After years of imprisonment in Papal prison in Rome, Bruno refused multiple requests to repent and reject his beliefs, and was sentenced to death by fire.
Until the invention of agriculture about 8,000 years ago, humans were hunter-gatherers, using tools to hunt game and forage for plants as sustenance.
While rare, some hunter-gatherer communities still exist. On North Sentinel Island in the Andaman Sea lives a hunter-gatherer tribe, among the last on earth to resist contact with the outside world.
In 1976, renowned astronomer Carl Sagan contacted a young high-school scientist living in the Bronx named Neil deGrasse Tyson. Sagan was a professor at Cornell at the time, and invited Tyson to spend a day in Ithaca in hopes that the budding astrophysicist would attend. Tyson chose to attend Harvard instead.
Originally airing in 1980, Carl Sagan’s “Cosmos: A Personal Voyage” was regarded as one of the first television programs to bring science to the masses.
"Our solar system’s hottest planet is Venus, the planet’s high levels of atmospheric carbon dioxide creating a greenhouse effect that renders the planet’s surface hotter than its neighbor Mercury..."
The way I understand it, the CO2-laden atmosphere maintains the greenhouse effect - with the help of strange cloud layers above - but did not "create" the greenhouse effect.