You think you have long-range vision? The Gulf Coast Exploreum (65 Government St.) is welcoming a luminary whose eyes and ears are attuned farthest of all.

For more than two decades, Dr. Seth Shostak has scanned the heavens looking for evidence of galactic neighbors. As former director and now senior astronomer for the SETI (Search for Extraterrestrial Intelligence) Institute, the astrophysicist searches for evidence of civilizations beyond our little blue globe. These artifacts aren’t arrowheads or pottery shards but electromagnetic waves.

“No matter what else aliens might be doing, it’s hard for me think they would not use electromagnetic radiation for communication purposes. We use it every day, all over the place, because it happens at the speed of light, it’s very inexpensive and simple to build the technology,” Shostak said.

Those who saw the 1997 film “Contact” get the drift. The film opening depicted the expanding aura of our television and radio signals that have rushed into the galaxy over the last century. Launched by NASA in the 1970s, SETI has surveyed the skies’ vast electromagnetic spectrum seeking similar byproduct elsewhere.

Shostak appears at Mobile’s hands-on science center on Thursday, Dec. 7, for a day of activities, culminating at 6 p.m. with his talk prior to a screening of Steven Spielberg’s “Close Encounters of the Third Kind,” filmed in Mobile.

Headquartered in Mountain View, California, the Institute’s primary tool is the Allen Telescope Array, a cluster of radio dishes nearly 300 miles northeast of San Francisco. They also employ optical telescopes around the world.

The most notable finding in decades of searching has been 1977’s “Wow! Signal,” named for a handwritten note on the data printout. Recently it was proffered the surprisingly strong burst from the constellation Sagittarius was a misidentified comet.

“To begin with, that comet wasn’t even in the right place in the sky,” Shostak said, before moving on to its wavelength. “No one’s ever seen a signal like this from any other comet.”

A redundancy failsafe provided roundabout confirmation. The telescope’s second receiver checked the same position about 70 seconds later and found nothing.

“That might be compatible with an intermittent signal by aliens. They just kicked off the transmitter after a minute and went to lunch,” Shostak quipped. “But it certainly isn’t a comet that was making a signal and then suddenly switched off in a minute.”

Neither do comets move fast enough relative to our observation point to make a difference.

The planets we’ve found orbiting other stars now number in excess of 4,400, with more than 2,200 discovered by the Kepler Space Telescope since 2009. The James Webb Space Telescope, boasting unprecedented resolution and sensitivity, is due for launch in 2019 and will enhance that knowledge.

The telescope’s ability to find chemical signatures through spectral analysis can reveal planetary conditions. Abundant hydrogen, oxygen or methane would interest SETI.

“That tells you there’s photosynthesis or bacteria or something else. That would be relevant and you’d immediately swing your SETI antennas in the direction of those planets, to see if there’s more than bacteria on those planets,” Shostak said.

Astrobiology is hot at the Institute. Nearly all of its 80 scientists are researching, experimenting and writing grants in that area. Several candidates for microbial life — Mars; Jupiter’s moons Ganymede, Callisto and Europa; Saturn’s moons Titan and Enceladus — aren’t so far flung.

“That would tell you there’s biology everywhere. That’s a big step because you have warm worlds with liquid water and atmospheres and all that stuff and there are tens of billions of them in the galaxy. If you find biology somewhere else in our solar system you can say it’s probably not an accident. It’s happened at least twice so that means it’s happened a lot of times,” Shostak said.

Shostak relays confidence we will find evidence of extraterrestrial life within the next two decades. Exponentially increasing technological power is a chief reason.

Criticism and doubts about SETI’s value still circulate. Shostak answered those in a 2009 TEDx talk when he pointed to its allure in increasing scientific literacy among other benefits.

An advanced civilization means self-annihilation isn’t inevitable. Sustained contact might allow us to short-circuit history, to advance more rapidly.

“It’s exploration. You can look back through history at societies that weren’t interested in exploration and they were subsumed by other societies. Ancient Egypt wasn’t interested in exploration but the Romans were, and as a result Egypt came under Rome’s grasp eventually,” Shostak said.

For more information on Shostak’s Mobile visit, call 251-208-6893 or go to exploreum.com.