Cosmic pluralism: science, religion, and possible populations on Venus

August 21, 2014 2:05 PM

In the seventeenth and eighteenth centuries it became possible to believe in the existence of life on other planets on scientific grounds. Once the Earth was no longer the center of the universe according to Copernicus, once Galileo had aimed his telescope at the Moon and found it a rough globe with mountains and seas, the assumption of life on other planets became much less far-fetched. In general there were no actual differences between Earth and Venus, since both planets orbited the Sun, were of similar size, and possessed mountains and an atmosphere. If there is life on Earth, one may ponder why it could not also exist on Venus. In the extraterrestrial life debate of the seventeenth and eighteenth centuries, the Moon, our closest celestial body, was the prime candidate for life on other worlds, although a number of scientists and scholars also speculated about life on Venus and on other planets, both within our solar system and beyond its frontiers. Venusians: the Planet Venus in the 18th-Century Extraterrestrial Life Debate (PDF), from The Journal of Astronomical Data (JAD) Volume 19, somewhat via NPR and their mention of amateur astronomer Thomas Dick's estimations of the populations of the other planets in our solar system (Archive.org online view of Celestial scenery, or, The Wonders of the planetary system displayed, 1845).
posted by filthy light thief (8 comments total)

Reading the 'NPR' link, it's nice to see Caleb Scharf's book get attention. I couldn't disagree more strongly with this Krulwich riff: "In the end, we may never know for sure if we are unique, extraordinary or commonplace. We just won't know. Ever." -- Not at all likely. I guess I'm a SETI optimist?

And on that vein, my favorite research paper in this area:

A search for life on Earth from the Galileo spacecraft
Sagan et al., 1993, Nature 365, 715 - 721
(Direct pdf link)

In its December 1990 fly-by of Earth, the Galileo spacecraft found evidence of abundant gaseous oxygen, a widely distributed surface pigment with a sharp absorption edge in the red part of the visible spectrum, and atmospheric methane in extreme thermodynamic disequilibrium; together, these are strongly suggestive of life on Earth. Moreover, the presence of narrow-band, pulsed, amplitude-modulated radio transmission seems uniquely attributable to intelligence. These observations constitute a control experiment for the search for extraterrestrial life by modern interplanetary spacecraft.
posted by RedOrGreen at 2:43 PM on August 21, 2014 [9 favorites]

Great link, RoG.
posted by benito.strauss at 5:09 PM on August 21, 2014 [1 favorite]

How dare you make such a rich post when I am so sleepy.
posted by neuron at 8:51 PM on August 21, 2014

I'm glad you're enjoying it.

To be fair, I made it hours ago, and the internet will be here tomorrow, and many days to follow.
posted by filthy light thief at 10:12 PM on August 21, 2014 [1 favorite]

Venus as a jungle hothouse was a staple of early science fiction, at least until we figured out just how HOT it was down there. (The first Venera probes had a lifespan on the surface measured in minutes.)
posted by fifteen schnitzengruben is my limit at 11:36 PM on August 21, 2014 [2 favorites]

Also worth mentioning (I don't know if this has been on MeFi before) is the 1835 newspaper hoax that detailed the discovery of life on every planet in the solar system. It was meant to be a satire or Thomas Dick but turned into a hoax when people believed it. Wikipedia, rather decent book on it.
posted by Hactar at 8:14 AM on August 22, 2014 [2 favorites]

Not at all likely. I guess I'm a SETI optimist?

I think you stopped reading too soon. The rest of the article is about how we're actually closer than ever to finding extraterrestrial life because we finally have the science and sufficiently powerful/sensitive tools to do it.
posted by Sangermaine at 12:22 PM on August 22, 2014

Forget Mars. Here’s Where We Should Build Our First Off-World Colonies
posted by homunculus at 3:26 PM on September 10, 2014