Questions at the boundaries between different scientific disciplines lead to some interesting research topics, including the origins of life, the survival of microbial life on the planets and moons of the Solar System, the search for intelligent life in the universe and even the ultimate fate of humanity and what it means to be an intelligent species with an understanding of the complexity of a living planet.
Reviews of what "habitability" means in an astrobiological context and how the biological sciences merge with astronomy in astrobiology.
In the search for signs of intelligent beyond Earth we often hear about researchers seeking radio signals or other directed/overheard communications from other worlds. Yet, despite looking for decades, we have found nothing. One possible reason for this may be that advanced civilisations destroy themselves (through warfare, over-exploitation of their planet, etc.) so soon after reaching a technologically advanced stage of development that we only have a vanishingly small chance of ever detecting them. However, what if the process of a civilisation destroying itself could be detected? Could detectable signs of extinct civilisations remain for long enough for us to find?
When astrobiologists talk about the "habitable zone" this usually refers to surface habitability. It is considered an easier task to detect signs of life living on the surface of a planet than underground or underwater. So it makes sense that missions searching for biosignatures prioritise planets that are likely to have inhabitable surfaces. However, outside of the surface habitable zone, planets and moons also have the potential to support life underground where conditions can be warm, wet and sheltered even when their surfaces are not. In "Circumstellar Habitable Zones for Deep Biospheres" we define a subsurface habitable zone to account for worlds like these.
Understanding how life first originated on Earth is crucial for understanding how other worlds might support life. If we know what conditions are required for life to begin, we can focus our search for life on planets that have, or have had, those conditions. "From Cytoplasm to Environment" explores the possibility that the earliest forms to emerge on Earth might have contained within them clues about the chemical make-up of the young Earth's environment; clues that may have been passed down through the evolutionary line and preserved in the cells of modern day organisms.