As potent space telescopes find out Earth-like planets, and SETI radio telescopes hear for transmissions from aliens, physical evidence for smart extraterrestrials may well be right in our backyard.
I am not conversing about flying saucers or oddball historical artifacts attributed to visits by so-named "space gods," nonetheless. Instead, I'm searching for some thing as mundane as the parts of interstellar probes that could have visited our solar system on several occasions over geologic time.
Watch Video: Will the actual ET be small green guys or little green germs?
Analysis: Are Alien Artifacts in Our Solar System?
If technological extraterrestrial civilizations are widespread in our galaxy, then they must have the wherewithal and curiosity to ship robotic probes to other star systems. We presently have five star-certain spacecraft destined to roam the galaxy without end: two Pioneer probes, a pair of Voyagers, and the New Horizons craft now dashing toward Pluto.
The aliens' motivations may possibly be the identical as ours if we found an Earth-like planet nearby, there would be an inescapable desire to deliver an unmanned craft to see what sorts of creatures are dwelling there. We would have a burning curiosity to behold how the power of biological evolution has performed out between the stars.
Analysis: Could Kepler Detect Alien Artifacts?
Seeking for alien "calling cards" in the solar system is not a new thought. It has been popularized in many science fiction tales and motion pictures. In Arthur C. Clarke's 1951 small tale The Sentinel, astronauts occur upon an alien-created pyramid on the moon that remains inscrutable.
A recent paper by Jacob Haqq-Misra and Ravi Kumar Kopparapu of Pennsylvania State University requires a new look at this twist on the Fermi Paradox: "In which Are They?"
The authors propose that an alien probe may be as tiny as a automobile, but no greater than a small-sized house. (All of the reconnaissance images here of lunar and Mars landers in shape that scale.)
SLIDE SHOW: Leading 10 Locations to Locate Alien Life
Certainly, for the propulsion demands of interstellar travel the less huge -- therefore smaller -- the payload, the greater. But finding it between our planets would be as challenging as finding a needle on a football area covered in three ft of hay, say the authors.
The researchers designed an equation that can be applied to a part of the volume of the solar system and decide no matter whether enough looking has been done to rule out any E.T. souvenirs.
They conclude: "Extraterrestrial artifacts may possibly exist in the solar system without having our expertise simply since we have not however searched adequately ( via news.discovery.com ).