Space & Innovation

Our Super-Advanced Alien Neighbors are Missing

After surveying some promising galactic candidates, an astronomer has concluded that there is little to no evidence for any super-advanced alien civilizations in our local universe.

After surveying some promising galactic candidates, an astronomer has concluded that there is little to no evidence for any super-advanced alien civilizations in our local universe.

If you're living in fear of alien invasions, this may seem like good news, but it is a perplexing - and, frankly, disappointing - finding based on our current understanding of the physical laws of our universe.

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Astronomer Michael Garrett of the Netherlands Institute for Radio Astronomy (ASTRON) and the University of Leiden came to this conclusion after studying the radio emissions coming from several hundred candidate galaxies and comparing the observations with infrared data. These galaxies were previously selected from 100,000 objects and are notable for their "unusually-extreme" emissions in mid-infrared wavelengths.

But how does mid-infrared and radio emissions equate to super-advanced alien civilizations? Well, it all comes down to alien waste - waste heat to be more precise.

In a nutshell, astronomers have been studying the emissions from galaxies that have the potential to host Kardashev Type III civilizations. The Kardeshev scale is a hypothetical measure of how advanced an alien civilization can be, based on its ability to harness energy. For example, a Type I civilization has the ability to harness all the available energy of its home planet; a Type II civilization has the ability to harness all the available energy from its star. Therefore, a Type III civilization has the incredible capability of harnessing all the available energy from its galaxy.

Just for reference, humanity is technically a Type 0 civilization and we'll not likely attain Type I status for another 100-200 years (if we even last that long as a civilization).

ANALYSIS: Could We Detect an Alien Civilization's Waste Heat?

A Type II civilization might use a Dyson sphere-like mega-structure to wrap its host star in a shell or system of rings to efficiently collect the vast majority of the star's radiation, converting it into energy that can be used to drive their super-advanced technological existence. One could therefore imagine a Type III civilization as a star-hopping race that has rapidly taken to other star systems, setting up an infrastructure of stellar energy collectors throughout their galaxy.

Science fiction this may sound, but it is based on logical conclusions for the growth of a sufficiently advanced civilization in a universe of sufficient age with effectively endless resources.

So, let's assume these Type III civilizations are out there; how can our humble technologies hope to detect such an advanced civilization?

No matter how advanced a civilization becomes, they will still be governed by physics and some galaxies should be glowing in these civilizations' waste heat with a specific mid-infrared signature. Basic physical laws state that energy cannot be created or destroyed, it can only be converted into other forms of energy. So, if our hypothetical Type III civilization has spread throughout its galaxy, setting up an interstellar network of Dyson sphere-like mega-structures around many of the galaxy's stars, these structures should be glowing in waste heat and therefore detectable in mid-infrared wavelengths.

ANALYSIS: Do Aliens Go Invisible by ‘Going Green'?

Taking a cue from work being carried out by Penn State University's G-HAT team (which is studying data from NASA's Wide-field Infrared Survey Telescope, or WISE), Garrett used radio data from the galaxies known to be extremely bright in mid-infrared wavelengths in the hope of weeding out which emissions can be explained by natural processes and which are artificial.

Key to Garrett's work is the "Mid-Infrared Radio correlation," a universal rule that seems to govern the emissions of most known galaxies. If galaxies known to generate a high flux of mid-infrared emissions also have a radio emission in line with this correlation, it is likely the mid-infrared emission is being generated by copious quantities of hot dust in galactic star-forming regions.

And in a new paper to be published in the journal Astronomy and Astrophysics, Garrett has found that this correlation holds true for the majority of the candidate galaxies, therefore indicating that these galaxies' mid-infrared emissions are caused by natural processes rather than Kardashev Type III civilizations.

"The original research at Penn State has already told us that such systems are very rare but the new analysis suggests that this is probably an understatement, and that advanced Kardashev Type III civilizations basically don't exist in the local Universe," said Garrett in an ASTRON press release. "In my view, it means we can all sleep safely in our beds tonight - an alien invasion doesn't seem at all likely!"

"Some of these systems definitely demand further investigation but those already studied in detail turn out to have a natural astrophysical explanation too. It's very likely that the remaining systems also fall into this category but of course it's worth checking just in case!"

How Aliens Can Find Us (and Vice Versa)

This research focuses on the emissions from civilizations in their most advanced state and certainly doesn't discount the existence of Type I or Type II civilizations - nor does it question the existence of extraterrestrial life - but it does pose a quandary, argues Garrett:

"It's a bit worrying that Type III civilizations don't seem to exist. It's not what we would predict from the physical laws that explain so well the rest of the physical universe. We're missing an important part of the jigsaw puzzle here. Perhaps advanced civilizations are so energy efficient that they produce very low waste heat emission products - our current understanding of physics makes that a difficult thing to do. What's important is to keep on searching for the signatures of extra-terrestrial intelligence until we fully understand just what is going on."

Indeed, astronomers can only work from our current understanding about how the physical laws of the universe work and use the growth of our civilization to model a hypothetical alien civilization. But this first pass of candidate galaxies appears to show that natural, not artificial, processes may be behind the mid-infrared emissions, making our little corner of intergalactic space a little more empty (of super-advanced alien civilizations at least).

For more about the Kardeshev Scale and its implications, check out this recent TestTube Plus+ video featuring Trace Dominguez and myself:

Source: ASTRON

Where are all the aliens? If an extraterrestrial civilization is advanced enough to harness the energy of its entire galaxy, we should be able to detect its waste heat -- but that search just became much harder.

Nov. 8, 2011 --

Despite the occasional report of an extraterrestrial sighting, be it through a microscope revealing curious shapes in a meteorite or a photo of wispy lights taken at the blurry end of a camera lens, aliens have yet to make contact with humans. Even the White House yesterday put out a statement declaring that the federal government "has no evidence that any life exists outside our planet, or that an extraterrestrial presence has contacted or engaged any member of the human race." Humans may not yet have encountered life outside of our planet, but many scientists see it as an inevitability. In 1960, astronomer Frank Drake came up with the now eponymous equation which provided an estimate of the number of civilizations in our galaxy. Although scientists continue to debate the application of his formula as well as alternatives, Drake's own solution to the equation is 10,000 civilizations, suggesting intelligent, technologically advanced life outside our planet is common. How these different civilizations, including our own, find each other is an important question for anyone here on Earth looking for extraterrestrials. Explore how aliens might stumble upon our planet -- and how we might actually spot them first.


Before we can began to search the skies, we have to start by narrowing down our options. Sticking within our own galaxy is a good start, since we're more likely to spot a neighbor closer to us than one further away. Astronomers may also elect to focus their attention on stars closer to the center of the Milky Way, where 90 percent of its stars are clustered. Furthermore, the stars here are a billion times older than the sun, giving life more time to develop biologically and technologically. Many stars are unsuitable for nurturing life, and even stars that do have the appropriate "spectral type" may host exoplanets inhospitable to life due to their location relative to their parent star, size or composition. These criteria would not only help us find aliens, but also help them find us. After all, Earth would stand out as a hospitable planet, according to a paper published in 2007 in Astrophysical Journal.

If aliens are looking for us, they're scanning the same, vast, dark and mostly empty expanse of space that we are. It's a good thing then that we're leaving the lights on to make it easier to find us. According to Abraham Loeb, of Harvard University and Edwin Turner, from Princeton University, by scanning the skies for artificial illumination as opposed to naturally occurring light sources, both human and extraterrestrial astronomers might be able to find signs of life. Existing telescopes would be able to see a city the size of Tokyo as far as the edges of our solar system.


For more than 25 years, the SETI Institute has been scouring the skies for signs of alien life. However, long before the institute was established, scientists have tried to catch a communication signal from another world. Scientists looking for alien signals use a combination of optical and radio telescopes, such as the one seen here. Dropping in on a signal without knowing the source of the communication is the tricky part, however, and researchers narrow down their search by targeting specific kinds of stars. With their citizen science program, SETI@home, the institute has enlisted three million additional observers analyzing data for traces of an alien signal.


Have aliens already stopped by for a visit, even though we weren't at the door to meet them? If they have, shouldn't they have left something behind? An artificial object of alien origin could be lurking in our solar system without our knowledge. As Discovery News' Ray Villard explains: "In a paper published in the 1960s, Carl Sagan, using the Drake Equation, statistically estimated that Earth might be visited every few tens of thousands of years by an extraterrestrial civilization." Further out beyond our solar system, aliens may have left what essentially amount to interstellar billboards large enough to be seen by, say, a planet-hunting telescope like Kepler. These last two scenarios, of course, envision an extremely technologically advanced civilization well beyond the engineering capabilities of humankind. At the same time, humans have sent spacecraft beyond the solar system, including Pioneer 10 and 11 as well as Voyager 1 and 2. All of these spacecraft are equipped with what are essentially calling cards for the human race -- small plaques in the case of the Pioneer spacecraft and golden records for the Voyager spacecraft (seen here).

SCIENCE CHANNEL: Top 10 Alien Sightings

Humans may rely primarily on fossil fuels as their primary means of energy, but that doesn't mean extraterrestrials in a far off civilization have the same power source. Solar power could be one option, though not quite with the same black panels we use on Earth. A super civilization could even tap into a black hole to meet its energy needs. If aliens are tapping to these cosmic bodies, that should make them all the more detectable from Earth. How would we know whether an alien race was relying on a black hole as a source of energy? As Discovery News' Ray Villard explains: "Tell-tale evidence would come from measurements that showed the black hole weighed less than 3.5 solar masses. That's the minimum mass for crushing matter into a black hole via a supernova core-collapse."

In one of the most unusual -- and highly unlikely -- first-contact scenarios, aliens would be able to recognize us by the level of greenhouse gas emissions we pump into our atmosphere. Not only that, according to a hypothesis put forward by researchers affiliated with NASA and Pennsylvania State University (though not directly tied with either institution), but aliens may use that as cause to wipe out the human race. In this bizarre set of circumstance, aliens view human advancement as a destructive force spiraling out of control. To avoid the threat of a future adversary, extraterrestrials clear out the competition.