Some of the specific questions and topics currently investigated by astrobiologists include:
- How are the raw ingredients of life formed, distributed, and recycled in the universe?
- What are the most reliable chemical signatures of primitive life?
- How do life and its host planet affect each other over time?
- How can we assess a planet's life history?
- How do you get from simple chemistry to self-replicating life forms?
- Life in extreme environments ('extremophiles'): is this how life started on Earth - and what we can expect to find on other planets?
- Large scale planetary impacts: ecosystem devastation and recovery.
- Extrasolar planets: finding them and evaluating their biological potential ('habitability').
- Searching for - and communicating with - extraterrestrial intelligence.
- Nervous systems: how did Earth affect their development - and how will they respond to the space environment?
- Muscle and Bone: what happens when weight-bearing structures no longer have weight to bear?
- Is life a natural consequence of planetary formation?
- What is the smallest, most fundamental level at which life perceives and responds to gravity?
- What will it take for terrestrial life to survive and adapt to environments in space and on other planets?
- How will human culture adapt and evolve in extraterrestrial environments?
- Philosophical and ethical aspects of these questions.
Although seemingly disparate, these many questions and topics have recently been combined very effectively into large interdisciplinary projects, as scientists now realize that many of our oldest fundamental questions ('Where did we come from?') cannot be fully understood unless viewed from a larger perspective than just our own Earth.
This is perhaps best illustrated by the work of the new NASA
Institute (NAI), founded in 1998. Now composed of 16 Lead Teams, which
together represent over 700 investigators across the US and Europe, the
NAI is devoted to the study of the origin and evolution of life in the
universe. Through the NAI, biologists are now working with astronomers
to describe the formation of life's chemical precursors, to discover new
planets and determine their habitability; with chemists to understand
transition from molecular interaction to life itself; with geologists to
search for evidence of water and key minerals on other planets; with
paleontologists and evolutionary molecular biologists to look for and
comprehend the earliest forms of life, as well as with climatologists,
planetary scientists, etc. Also of great interest to NASA (particularly
in the new context of President Bush's 'New Vision for Space
Exploration' Program) and part of the NAI research is the study of the effects of
outer space on living organisms from Earth, including the health effects
of prolonged space travel on humans.