SETV Logo [Image]
A Scientific Search for Visitation
from Extraterrestrial Probes

A New Search Model in the Quest to find ETI

Address of this site

Part 2. Motivation for SETV

The search for extraterrestrial visitation is motivated not only by the writings of other authors on the subject of interstellar probes, but also by the awareness of the progression of our own probe technology. Included in this awareness are Earth's advancements in communication technology, growing understanding of exobiology and ongoing research of new possiblities to enable travel across vast distances. Also in response to the public's growing need to understand "whether we are alone in the Cosmos."

ETI Probes and Their Missions

Using our own technological capabilities and achievements as a guide we can explore a likely range of ETI probe missions to our star system. Missions to unlock the secrets of our solar system involves the construction of machines built using available engineering technologies. With the exception of the Apollo moon landings, Space Shuttle, Mir and Skylab, all of the other physical solar system explorations have utilized robotic probes of one kind or another.

At this time our civilization has a remote presence in the solar system that includes twelve active space probes, with more than 102 space probes successfully launched since 1959.

Launching very reliable autonomous missions will ease the burden on deep space network telecommunications resources that are in high demand because of the growing numbers of robotic probes. Not needing to communicate with a probe for a year or more has value. For very long duration missions not needing to maintain contact for a long period of time is not only desirable, it's mandatory.

The hardware and software needed to build autonomous, intelligent flight systems will be complex and depend on the existence of a number of advanced technical implementation strategies. Two of these advancements are micro/nano-technology and an embedded sofware co-design programming language (Wong, 1998).

The use of more densely packed hardware structures with embedded software leads to lower volume, less mass, more diverse, and more reliable instruments. This will lead to smaller space probe designs with the full functionality of their larger and less evolved counterparts. This is the current trend in Earth space probe design, and if we extrapolate this trend to say >100 years in the future, the majority of the probes launched will be small, smart and autonomous (Tough, 1998).

But, the entire fleet of probes launched from other civilizations won't all be small, there will still be a need for larger probes especially the ones on interstellar voyages that will require added mass for fuel storage. Furthermore, large intestellar probes can act as seed pods for any smaller probes they are carrying. Indeed, there will continue to be a range of probes sizes and shapes well into the future, from nano to macro.

With this realization we should expect highly advanced probes from multiple or single ETI civilizations to exhibit a wide range of sizes and shapes. We must avoid allowing our subjective ideas about what ETI probes should look like or behave like, to cause us to dismiss certain shapes as being probes. For every geometric combination of shapes and sizes (with at least one axis of symmetry), we can imagine there probably exists an ETI probe that has a similar appearance, even including the double pie-pan or so-called "flying-saucer". ETI robotic probes will come in a diverse range of shapes, sizes and configurations, and we should not be surprised or disturbed by this. -- they will not all look like Hubble or the Mars Pathfinder.

We have already touched on our civilization's desire to launch deep space probe missions; at this time they are mainly for scientific discovery and technology validation. But once an ET civilization has overcome the major technological challenges, such as the great-distance-travel problem, what might might their probe missions be about? There are many possibities, but these four categories of ETI interstellar probe missions seem probable:

    1. Scientific exploration and discovery
    2. Military reconnaissance
    3. Commercial resource and colonization reconnaissance
    4. Tourism and sight-seeing

Discriminating between the types of ETI robotic probe missions and agendas, remains a matter of conjecture. All we can do is examine how we would conduct the different missions listed if we had the technology to do so.

All four mission types require the approaching probe to decelerate a substantial amount before it reaches our solar system, provided ETI probes employ propulsion systems similar to that developed on Earth or unless it is a sub-luminal relativistic fly-by, Probes can enter our solar system from just about any direction. In all likelihood they will approach from above or below the ecliptic plane where collisions with dust particles will be minimal. Also, interstellar regions with higher star densities may produce more intelligent civilizations and therefore be a source of more robotic explorations.

It is reasonable to expect that some robotic probes would place themselves into a heliocentric orbit. Remarkably, a telecopic observation of an object in 1991 may be an autonomous probe in solar orbit (Steel, 1995).

Some authors (Kuiper, 1977; Freitas, 1980) have considered that ETI probes visiting Earth would find it necessary to hide themselves from our detection systems until they have assessed our technological level or potential threat. For defensive or "first strike" purposes, we see our own need to build craft that are "stealth by design", "low observable" (LO), "stealth by intent" or "stealth through technological efficiency". We should expect LO ETI probes to be a distinct possibility. Physics mandates that there are only so many stealth strategies that can be used, even by ETI probes. Cloaking devices to mask a probe thermally, optically and from RADAR, as often depicted in science fiction, may not be necessary. Simple camouflage through mimicry works well in nature, and may be the technique of choice used by Earth visiting probes already experienced in surveillance. One author, through his own instrumented observation study, suggested that ETI surveillance probes may sit stationary over a certain region appearing as "pseudo-stars" (Rutledge, 1981); unless one was very familiar with the night time star positions, magnitudes and motions, the probe would go unnoticed. Another camouflage technique may be entering the atmosphere with either the look and trajectory of a meteor, or hidden within a meteor shower. The observed phenomenon of "dark meteors" (Malau, 1995; McBeath 1995,1996) may be a technique used by ETI probes to pass through the atmosphere on a meteoric trajectory, but without any associated optical train or signature. Another technique may be to mimic our commercial aircrafts' aggregate features (flashing red-green lights, sounds, speeds, motions), with just enough "thinly veiled" accuracy, to only draw a quick and uninterested glance (Cornet, 1996). Of course, this entire discussion of ETI probe low observability behaviors assumes that humanity itself is the subject of interest and advoidance; this may not be the case at all, but it is a realistic place to begin.

Probe missions related to extended environmental surveys would be considered "low risk" if they were confined to isolated, sparsely inhabited regions, such as deserts or polar ice caps, where little or no evidence of humans or terrestrial technology is found. A highly advanced probe might employ an adaptive multi-level risk program to avoid danger. Observed behaviors employing hazard avoidance, learned through prior encounter experiences, will probably make a probe appear intelligently controlled. This could lead to a misperception that the probe contains living occupants, intelligent according to our anthropocentric understanding of the concept. The size, shape and/or behavior of a highly advanced ETI probe might be 'seen' as being crewed and operated by intelligent ETs. For example, in 1988 the un-crewed Russian space shuttle Energia-Buran was launched into orbit and successfully landed under complete computer control (Jenkins, 1996). Watching it come in for a landing an onlooker might conclude it was 'intelligently' piloted, and might even imagine seeing a cosmonaught at the controls. If ETI probes do visit Earth, to avoid prospective dangers they will probably attempt to minimally interact with our local environment. Even so, they will very likely be detectable using contemporary sensing technologies.

Possibility of Life Beyond Earth

Part 3. Search Efforts for ETI

If you have Administrative questions you may send them to:
Please direct Technical questions to:

Permission to add a link to this web site from within a frames-based web site is prohibited without the express permission of OSR administration.

| Home | Top | Go Back |

Entire website (including text and images) copyright © The Organization for SETV Research (OSR), except as noted.
This page was last updated on Saturday, August 04, 2002.