Who Are the Space Invaders? Planetary Protection and the Role of Biological Interactions between Extraterrestrial and Terrestrial Biospheres.

Exploring our solar system and returning pieces of it to Earth is a central part of the existential quest to search for life beyond our home planet. Understanding the biosafety and biocontamination implications of landing on a planetary body or in bringing pieces of our solar system back to our home planet are the two themes that are central to planetary protection, a discipline that is unique to spacefaring nations. The nature of planetary protection is twofold: (1) to ensure that we minimize our own terrestrial microbial footprint on other planets and moons (planetary bodies) in our solar system (forward contamination), and (2) to ensure that we minimize the potential impact of returning samples from another planet or moon to Earth (backward contamination).

Planetary Protection Knowledge Gap Closure Enabling Crewed Missions to Mars.

As focus for exploration of Mars transitions from current robotic explorers to development of crewed missions, it remains important to protect the integrity of scientific investigations at Mars, as well as protect the Earth's biosphere from any potential harmful effects from returned martian material. This is the discipline of planetary protection, and the Committee on Space Research (COSPAR) maintains the consensus international policy and guidelines on how this is implemented. Based on National Aeronautics and Space Administration (NASA) and European Space Agency (ESA) studies that began in 2001, COSPAR adopted principles and guidelines for human missions to Mars in 2008.

Planetary protection technologies for planetary science instruments, spacecraft, and missions: Report of the NASA Planetary Protection Technology Definition Team (PPTDT).

Planetary bodies like Mars, Europa, and Enceladus pose the question, "How to study them without contaminating them and destroying future prospects to detect life, if it is there?" The natural trade-off, of course, is that the cleaner your spacecraft, the more you can explore such a body without risk of contaminating it. As chartered by NASA Headquarters, the Planetary Protection Technology Definition Team (PPTDT) was asked to provide a report covering six different areas related to the engineering and technology challenges of implementing planetary protection requirements on solar system exploration missions.

From Planetary Quarantine to Planetary Protection: A NASA and International Story.

This paper treats the very specific history of one aspect of space policy and how it, or more specifically its name, developed in the first two decades of the Space Age. The concepts of preventing the biological and organic contamination of other planetary bodies, which also protect the biosphere from the consequences of finding extraterrestrial life and returning it to Earth, were established in the late 1950s with the beginning of the Space Age. Within their first decade, those concepts were labeled "planetary quarantine," a name that suggested the concepts but unfortunately came with latent baggage of its own.

It's Time to Develop a New "Draft Test Protocol" for a Mars Sample Return Mission (or Two…).

The last time NASA envisioned a sample return mission from Mars, the development of a protocol to support the analysis of the samples in a containment facility resulted in a "Draft Test Protocol" that outlined required preparations "for the safe receiving, handling, testing, distributing, and archiving of martian materials here on Earth" (Rummel et al., 2002 ). This document comprised a specific protocol to be used to conduct a biohazard test for a returned martian sample, following the recommendations of the Space Studies Board of the US National Academy of Sciences.

Aspergillus penicillioides differentiation and cell division at 0.585 water activity.

Water availability acts as the most stringent constraint for life on Earth. Thus, understanding the water relations of microbial extremophiles is imperative to our ability to increase agricultural productivity (e.g.

Glycerol enhances fungal germination at the water-activity limit for life.

For the most-extreme fungal xerophiles, metabolic activity and cell division typically halts between 0.700 and 0.640 water activity (approximately 70.

A new analysis of Mars "Special Regions": findings of the second MEPAG Special Regions Science Analysis Group (SR-SAG2).

A committee of the Mars Exploration Program Analysis Group (MEPAG) has reviewed and updated the description of Special Regions on Mars as places where terrestrial organisms might replicate (per the COSPAR Planetary Protection Policy). This review and update was conducted by an international team (SR-SAG2) drawn from both the biological science and Mars exploration communities, focused on understanding when and where Special Regions could occur. The study applied recently available data about martian environments and about terrestrial organisms, building on a previous analysis of Mars Special Regions (2006) undertaken by a similar team.

Carl Woese, Dick Young, and the roots of astrobiology.

The beginning of the space age in the late 1950s gave rise to innovative and interdisciplinary research concepts and perspectives, including the concept of "exobiology" as a way to approach the fundamental aspects of biology through a study of life outside of the Earth, if it existed. This concept was embodied by NASA into its formal Exobiology Program and into the philosophy of the program both before and after the Viking missions that were launched to Mars to search for signs of life in 1975. Due to both management flexibility and an acceptance of the interdisciplinary nature of the problem of "life in the universe," NASA program managers, and particularly Richard S Young who ran the Exobiology Program beginning 1967, have made some excellent investments in paradigm altering science of great use both on Earth and on future space missions.

A THEORY OF FAUNAL BUILDUP FOR COMPETITION COMMUNITIES.

Invasion-structured communities have more species than do coevolution-structured communities assembled using the same resource distribution. Species in invasion-structured communities are tightly packed, occupying the upper portion of the resource axis; species in coevolution-structured communities are more widely spaced, and most are located in the lower portion of the resource axis. As a consequence, coevolution-structured communities tend to be more stable than comparable invasion-structured communities, but more open to invasion.