Scientists provide possible reasons why we have not heard from aliens

Nov 7, 2011 16:00 GMT  ·  By
Even nearby places such as Mars may contain alien artifacts, without us knowing about it just yet
   Even nearby places such as Mars may contain alien artifacts, without us knowing about it just yet

When humankind decided to send its coordinates into space, aboard gold disks installed on the Pioneer space probes, many started wondering whether a potential alien civilizations may have sent a similar call into space. Two experts now provide an explanation for why we heard nothing from aliens.

The reasoning in itself is not flawed. If extraterrestrials exist, then they would undoubtedly at least consider the idea of communicating with whoever else may be out there. Some civilizations may choose for example to remain quite, preferring safety over exploration.

Of those that decide to make their presence known to others, some may send spacecraft like our own, in a bid to send news of their existence far and wide. However, the search for such alien artifacts has thus far produced no tangible result.

A team of two Pennsylvania State University (Penn State) postdoctoral researchers proposes that humans simply haven't looked in enough places to be able to draw a clear conclusion from their search.

In other words, we've only covered a minuscule portion of outer space with our searches, not enough for our chances of finding something to become statistically significant. Such progress could be achieved, for example, when the entire Milky Way is scanned thoroughly.

The new explanation is significant especially when applied to the Fermi paradox, which renowned scientist Enrico Fermi formulated some time ago. The question calls for an explanation as to why, out of the large number of proposed intelligent species, we cannot detect a single one.

The new proposal is only the latest to be added to a list of potential answers. Other entries include the possibility of life actually being much rarer than calculated, that alien lifeforms destroy themselves upon reaching a certain degree of technological development, or that some may prefer isolation.

“The vastness of space, combined with our limited searches to date, implies that any remote unpiloted exploratory probes of extraterrestrial origin would likely remain unnoticed,” say Jacob Haqq-Misra, of the Rock Ethics Institute, and Ravi Kumar Kopparapu, of the Earth and Environmental Systems Institute.

The team's paper on the issue was accepted for publication in an upcoming print issue of the renowned journal Acta Astronautica. The work has already been published online, in the journal ArXiv.

“Extraterrestrial artifacts may exist in the solar system without our knowledge simply because we have not yet searched sufficiently. Few if any of the attempts would be capable of detecting a 1 to 10 meter (3 to 33 foot) probe,” Haqq-Misra and Kopparapu explain in the paper.

“Searches to date of the solar system are sufficiently incomplete that we cannot rule out the possibility that nonterrestrial artifacts are present and may even be observing us. The completeness of our search for nonterrestrial objects will inevitably increase as we continue to explore the Moon, Mars and other nearby regions of space,” they conclude.