Journal of Cosmology, 2010, Vol 5, pages xxx In PRESS Cosmology, January 13, 2010 From the Moon to the Moons: Encedalus, Ganymede and Europa. The Search for Life and Reliable Biomarkers J. Chela-Flores, Ph.D., The Abdus Salam ICTP, Strada Costiera 11, 34014 Trieste, Italia, and Instituto de Estudios Avanzados, IDEA, Caracas 1015A, República Bolivariana de Venezuela Abstract The recent renewal of interest in exploring the Moon has led to further novel possibilities for the exploration of the Solar System. It is in the outer Solar System where the biggest challenges await our efforts, both in the development of instrumentation and in the clarification of the biosignatures that should be clear indications of life, as opposed to non-life signals. We argue that in the present-day larger scope of cosmology we can undertake one of the most important missions of the space sciences within our own solar system, namely the search for and discovery of a second genesis. This may be accomplished by landing on Europa's surface. We conclude that the implementation of penetrators in future exploration of the outer solar system is worthy of all the financial and technical support that will be needed, both at the national, as well as at the international level. Keywords: Astrobiology, instrumentation, exploration of the solar system, Europa, Enceladus, Biosignatures 1. Introduction It seems appropriate for a journal devoted to cosmology to encompass the field of astrobiology and to move beyond the "anthropic principle" of quantum physics, the standard astroparticle physics and astrophysics that dominate the field of classical cosmology. In the standard "Big Bang" cosmology the universe began 13.8 billion years ago, then life arose on Earth in the last 30% of the history of the cosmos. How life arose, is as yet unknown, though we can say with certainty that life emerged out of baryonic matter. Life as we know it is based on carbon. How carbon was incorporated into life remains unknown, nor do we fully understand the full chemical pathways, which led to life. However, beginning with the work of Stanley Miller and his landmark contribution in 1953, and the subsequent discoveries in organic chemistry, it is likely that the full chemical pathway for life will eventually be understood. With a few exceptions (Shapiro, 2009 and references therein), attempts to understand the origin of life have reasonably assumed that the Earth is a cradle of life. However, if life was not delivered to this planet via mechanisms of panspermia, and ruling out, for the moment, the possibility of the interplanetary exchange of life (Mahaney and Dohm 2010), then certainly it is reasonable to assume that life could have begun independently on other planets and moons, including Titan (Naganuma and Sekine 2010), Io (Schulze-Makuch 2010), Mars (Levin 2010), and Europa. The same steps of chemical evolution that eventually led to the evolution of the first cells on Earth could also have taken place on other worlds, limited only by resources, the availability and abundance of water, distance from the Sun, and the capacity to develop a life-promoting atmosphere (Lal 2010), although as in the case of Europa habitability does not necessarily need an atmosphere, as we argue in this paper. Thus it is reasonable to consider the phenomenon of life and its evolution in the Solar System and, more appropriately, in the context of the space sciences, including cosmology. It is indeed timely to begin inserting in a universal context not only chemical evolution, but to go beyond and to begin considering the phenomenon of life on Earth, in the Solar System and, more appropriately, in the context of the space sciences, including cosmology—the proper perspective for the new science of astrobiology. 2. A Return to the Moon: Preliminary Steps in the Exploration of our Solar System In spite of the fact that Neil Armstrong’s first step on the Moon was such a tremendous step forward in the exploration of the Solar System, unfortunately low-Earth orbits have constrained all subsequent efforts during following four decades. Fortunately, unlike forty years ago when the exploration of the Solar System was the exclusive realm of two nations (America’s NASA and the Soviet Union’s Roskosmos), today there are major international efforts in progress, including the European Space Agency (ESA), the Indian Space Research Organisation (ISRO), China National Space Administration (CNSA) and the Japan’s Independent Administration on the Exploration and Aviation of Space Study and Development Organization (JAXA). Humans may again set foot on the moon. Naturally, the next step would be other planets, perhaps using the moon as a base and stepping stone for Solar System exploration. We are now aware of the presence of water on the lunar surface. Since water can accumulate on the Moon, and given evidence that early Mars may have had abundant water, then it is certainly reasonable to assume that this precious resource so vital to life, may have also accumulated on other moons and planets. Due to the Galileo and Cassini Huygens missions we are now in possession of vital information of the moons of the outer Solar System. We now have several intriguing candidates that may harbor at least primitive life, including Titan (Naganuma and Sekine 2010) and especially Europa, where an ocean of water may freely circulate beneath its overlying icy crust. What makes these discoveries even more intriguing are super-Earths orbiting in the habitable zones of other solar systems. We are rapidly learning that our outer Solar System may be a typical of other solar systems. If true, then life may be ubiquitous, and on some planets, biology may have evolved in ways similar to life on Earth (Shapiro, 2009 and references therein). 3. Penetrators as Possible Landers on the Moons of the Outer Solar System Penetrators are instruments that consist of small projectiles that can be delivered at high velocity to reach just beneath the surface of planets or their satellites for probing samples of surface and subsurface chemical elements and biomarkers. So far delivering them to Mars has encountered technical difficulties. The MARS-96 robotic spacecraft scientific mission was launched in November 1996. The spacecraft had a malfunction in the third stage of the rocket and re-entered the Earth's atmosphere, falling into the Pacific Ocean (Surkov and Kremnev, 1998). Unfortunately, in December 1999, a second attempt by NASA failed to land successfully in the north- polar region (Gavit and Powell, 1996). The penetrator technology continues to undergo technological advances that will make them vital to forthcoming missions for the exploration of the Solar System. The development of penetrators by the UK Penetrator Consortium is expected to make a variety of in-situ measurements at widely separated locations on the Moon and beneath the lunar surface (Smith et al., 2008, Gowen et al., 2009). Japan and Russia have valuable experience with penetrator technology and its use for the search of biomarkers. For example, a penetrator probe was developed in the course of the former Japanese LUNAR-A project (Mizutani et al., 2000). It is now being developed to improve the sensitivity required to detect small deep moonquakes, as well as other types of lunar seismic events into the lunar regolith. Preliminary results indicate that newly developed penetrator technology can function properly after impact (Yamada et al., 2009). 4. Saturn's Moon Enceladus and the Possibility of Life Enceladus is a moon of Saturn and reflects almost 100% of the sunlight that strikes it (cf., Fig. 1). High-resolution Cassini images show icy jets and towering plumes ejecting large quantities of particles at high speed (cf., Fig. 2). It also it has a variety of terrains, including canyons, some tectonically deformed terrain, and very few impact craters in the south polar region all of which indicates that this little moon is geologically dynamic and active. In addition, the Visual and Infrared Spectrometer (VIMS) instrument detected crystalline water ice along the surface that may have formed in the last 1000 years and may have been thermally altered in the recent past. Moreover, simple organic compounds were also detected. The best explanation is that a warm liquid water ocean lies beneath the surface, heated possibly secondary to tidal forces. In 2009, ammonia was found and can be produced biologically, acting as an anti-freeze. Particles of ice analyzed by Cassini revealed that the surface ice was composed of salt water. Thus there is evidence that a warm salt-water ocean may exist beneath the surface of this tiny moon. Coupled with evidence of salt water, ammonia, and simple organic compounds including carbonates, there is thus sufficient motivation for discussing the possibility of life on this moon. Fig. 1. An artist's conception of the landing of the Huygens probe. Portions of the "tiger stripe' fractures are prominent along the diagonal of the image. The plumes emanate from the regions that are on or near these geologic features. Credit NASA/JPL/ Space Science Institute. Fig. 2. The plumes of ice and water vapor from Enceladus' south pole. Credit NASA/JPL/ Space Science Institute There is now ample evidence that many species of Archaea and other microbes can survive and flourish under what until a few years ago were considered "life- neutralizing" conditions. Extremeophiles flourish in deep-sea thermal vents, at the bottom of the ocean near volcanic vents, in pools of radioactive waste, in salt, and nearly 2 miles beneath the surface of the Earth in the absence of oxygen or sunlight. Therefore, it is not unreasonable to assume that microbes could also flourish on Enceladus where similar conditions prevail. 5. Europa and the Possibility of Life? Europa is the second nearest Galilean moon and its radius is 1565 km, not too much smaller than our Moon's radius.