"In the previous post, Socrates brought up that extraterrrestrial civilizations may manifest themselves as thermal infrared sources in the outer reaches of our galaxy."

From distance of say Pluto, with our current telescopes could not detect any thermal infrared of our civilization.
One of most volcanic bodies in the this solar system is Io, we didn't know this before we sent a probe there.

"Before the Voyager probes visited Jupiter, if you had described Io to a literary critic it would have been declared overwrought science fiction. Jupiter's strange moon is literally bursting with volcanoes. Dozens of active vents pepper the landscape with volcanic rings the size of California. The volcanoes themselves are the hottest spots in the solar system with temperatures exceeding 1800 K (1527 C) about 1/3 the temperature of the surface of the Sun.
...
One week prior to Voyager 1's encounter with Jupiter, Stanton Peale published a paper suggesting that tidal heating might produce volcanism on Io. His prediction was spectacularly confirmed on March 8, 1979 when Voyager 1 captured geyser like eruptions spewing material hundreds of kilometers above Io's surface. "
http://www.solarviews.com/eng/iovolcano.htm

"Now the nearest star to the Sun is Proxima Centauri which is located at a distance of 4.3 light years (one light year is the distance traveled by light in one year). Now, 1 light year is 63,270 AU, which means that the distance to the nearest star is 272,061 AU. "
http://curious.astro.cornell.edu/question.php?number=374

We are 1 AU from the sun, Jupiter is 5.20 and Pluto is 39.5 AU.