All this time, science enthusiasts lived in hope. Hope of finding extraterrestrial life. But all such notions have been put to rest with a recent study that has shown that advanced alien civilizations are probably absent or extremely rare in our universe.

Scientists had thought that such advanced alien civilizations could have been detected by waste heat, as these civilizations would have harnessed enormous energies on the scale of the stellar output of their own galaxy. These civilizations and their energies, calculated on a galactic scale, called the Kardashev Type III civilisations, were to be to be detectable in the mid-infrared part of the spectrum due to the waste heat.

But now professor Michael Garrett (ASTRON & University of Leiden) says that most of these systems present emission that is best explained by natural astrophysical processes. Garrett used radio measurements of the galaxies to come to this conclusion

"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. In my view, it means we can all sleep safely in our beds tonight - an alien invasion doesn't seem at all likely!" said Garrett, according to ASTRON, the Netherlands Institute for Radio Astronomy.

"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!" said Garrett while continuing to explore a few galaxies that lie off of the astrophysical correlation, reports Astro Biology Magazine.

"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," said Garrett while disclosing his plans to look for these less advanced civilizations, according to Space Daily.