Astrobiology is rapidly gaining the worldwide attention of

scientists, engineers and the public. Astrobiology’s captivation is

due to its inherently interesting focus on life, its origins and

distribution in the Universe. Because of its remarkable breadth as

a scientific field, astrobiology touches on virtually all disciplines in

the physical, biological and social sciences as well as

engineering. The multidisciplinary nature and the appeal of its

subject matter make astrobiology ideal for integrating the

teaching of science at all levels in educational curricula. The

rationale for implementing novel educational programs in

astrobiology is presented along with specific research and

educational policy recommendations.

Addresses

Department of Microbiology, NSF Astrobiology IGERT Program,

University of Washington, Box 357242, Seattle, WA 98195, USA

Current Opinion in Biotechnology 2003, 14:347–354

This review comes from a themed issue on

Science policy

Edited by Rita R Colwell

0958-1669/03/$ – see front matter

2003 Elsevier Science Ltd. All rights reserved.

DOI 10.1016/S0958-1669(03)00073-9

Abbreviations

NAI NASA Astrobiology Institute

NASA National Aeronautics and Space Administration

NSF National Science Foundation

SETI search for extraterrestrial intelligence

Introduction

This article introduces the multidisciplinary field of astrobiology,

which bridges the gap between the biological and

physical sciences and engineering. In addition, recommendations

are made for astrobiology to serve as an

alternative model for teaching science and engineering

at all levels of education including primary, secondary,

undergraduate and graduate students. I am writing this

article largely based upon the experience that my colleagues

and I have had in developing a PhD program in

astrobiology at the University of Washington.

What a difference a word makes

For four decades the National Aeronautics and Space

Administration (NASA) sponsored a science program on

exobiology, a term which, by definition, refers to the

study of life outside Earth. Excluding Earth and earthlings

seems inappropriate for at least three reasons. First, it

is ironic to disregard Earth, because it is the only place so

far known in the Universe where life actually exists.

Second, exobiology implies that there is something very

different and strange about creatures from other planetary

bodies. Why shouldn’t all living matter in the Universe

share common properties in the same sense as other

matter? Third, the study of life on Earth, including its

evolution and diversity, provides valuable clues and lessons

for the exploration of other worlds that may harbor

life. After all, if we cannot understand life, its origins and

its limits on Earth, how can we possibly begin to identify

life and efficiently study it elsewhere?

The perception of scientists and lay people has changed

since NASA introduced the term astrobiology, because

it optimistically embraces the study of all life in the

Universe, including life on Earth. The introduction of

the term astrobiology coincided with NASA’s establishment

in 1998 of the NASA Astrobiology Institute (NAI),

which now encompasses about a dozen universities and

research centers at NASA and elsewhere (http://www.nai.arc.nasa、gov). In the five years since the NAI began as

a virtual institute, an international effort has linked its

astrobiology program to those of several other countries.

These include Spain (Centro de Astrobiologia), the United

Kingdom (UK Astrobiology Forum and Network), France

(Groupement de Recherche en Exobiologie), Europe

(The European Exo/Astrobiology Network Association)

and Australia (Australian Centre for Astrobiology).

Why is astrobiology so appealing?

How is it that astrobiology has captured the curiosity,

fascination and admiration of so many? Surely much of its

appeal has to do with the great metaphysical questions of

astrobiology. Where did we come from? How does life

begin and evolve? What is life’s future? Does life occur

elsewhere in the universe?

This young and vigorous field holds great expectations

that these questions can and will be answered. Herein lies

the appeal of astrobiology. Not only is the subject matter

of broad interest to virtually all of us, it is basic to our

perception of the world in which we live. Furthermore,

scientists are sanguine about our ability to answer at least

some of these questions in the foreseeable future. So, it is

not surprising that the air bristles with excitement and

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anticipation at astrobiology meetings as scientists report

how they are unraveling the mysteries of life, its tenacity,

fragility, distribution and origins.

The transcendent nature of astrobiology

Astrobiology is remarkable in its extreme breadth and

therefore its potential for multidisciplinary education

and research. It touches on virtually all fields of science

and engineering. As a result it is perhaps unique among all

disciplines. Astrobiology is unlike, for instance, biology

which is exclusively centred on the study of all aspects of

life on Earth. Astrobiology, by contrast, considers questions

that transcend our planetary boundary. When biologists

ask the question ‘What is life?’ they are constrained

by the range of life forms on Earth. However, when the

astrobiologist asks the same question, all boundaries are

removed. The astrobiologist is no longer confined to life

on Earth, but is forced to conjure possibilities beyond the

requirements of water and the DNA! RNA! protein

dogma. Indeed, imagination is the only limitation to the

astrobiologist’s thinking, although it is a severe one. To

test your own imagination, contemplate the question

‘What is life?’ and propose one or two truly alternative

life styles to that which we know so well.

A special multidisciplinary challenge for astrobiology

relates to the dating of early events on Earth and provides

another example of its transcendent nature. Geologists

working with paleontologists provided us with the

Geological Timetable during the last half of the 20th

century. From this effort, much was learned about the

past 600 million years of animal and plant evolution.

However, little is known about early evolution, that is,

from the Precambrian Eon after Earth’s formation about

4.5 billion years ago until 600 million years ago. Our only

hope to uncover this information is through the mutual

efforts of geologists, micropaleontologists, microbiologists

and phylogeneticists. Fossils alone cannot answer

the important questions about the order in which processes

such as methanogenesis and sulfate reduction

occurred, because microbial fossils are too simple. Chemical

biomarkers for processes and specific microbial

groups are needed in conjunction with phylogenetic

analyses. Already astrobiologists from the various disciplines

are talking with one another about resolving this

issue through multidisciplinary efforts.

So, not only does astrobiology provide genuine appeal to

all, but it is perhaps unique in its transcendence of

science. It encompasses aspects of biology, astronomy,

physics, planetary sciences, chemistry and geology as well

as the social sciences. Example topic areas in astrobiology

are given in Box 1.

Interdisciplinary astrobiology research

Much of the exciting research in astrobiology lies at the

interface between two or more disciplines. For example,

microorganisms are intimately involved in rock weathering

processes. From an astrobiological perspective,

biological weathering processes leave ‘signatures of life’

such as specific biological compounds or microbial fossils

that could be used to identify life on rocks from other

planetary bodies such asMars. The traditional training of

geologists and microbiologists does not prepare PhD

graduates to study these geobiological activities by themselves;

however, in astrobiology, scientists work together

in designing and testing hypotheses and thereby expanding

our understanding of fundamental but poorly studied

processes.

In our astrobiology PhD program at the University of

Washington, we have seen examples of interdisciplinary

work that have resulted in unique perspectives. It is

noteworthy in this regard that it is not always the faculty

who have made these breakthroughs, but it is often our

PhD students. One example of this is work carried out by

an astronomy student, John Armstrong, and a biology

student, Llyd Wells, who have worked with an astronomy

faculty member, Guillermo Gonzalez. They proposed

that the Moon, as ‘Earth’s attic’, probably contains

rocks with microbial fossils and other signatures of life

from Earth that were ejected to the Moon as it drifted

away from Earth after its formation. These fossils would

be well preserved, because they have not been exposed

to weathering and tectonic processes on Earth. These

rocks are therefore likely to contain geochemical and

fossil evidence that may tell us much about early Earth

history [1]. In a second paper, they suggest that, had a

major sterilizing impact occurred on Earth following the

evolution of life, rocks subsequently ejected from the

Moon by an impact event could have been brought back

to Earth to re-seed it [2]. These papers are having a

major influence on NASA’s thinking concerning the

possibility of launching amission to theMoon to retrieve

early Earth rocks.

Another example of interdisciplinary collaboration involves

two of our faculty members. Peter Ward and Don

Brownlee, a paleontologist and an astronomer, respectively,

have collaborated in writing two recent provocative

books on astrobiology, ‘Rare Earth’ and ‘The Life and Death

of Planet Earth’ (Box 2).

Box 1 Example topic areas in astrobiology.

Star birth, death and recycling of elements

Formation of planetary systems

Origin and evolution of life

Search for extraterrestrial biosignatures

Habitable planets and satellites within and beyond our solar system

Earth’s early geosphere, hydrosphere and atmosphere

Earth’s early biosphere

Mass extinctions and diversity of life

Fossil and geochemical evidence of early life

Life in extreme environments

Planetary protection

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Astrobiology as an exciting new field for

research

In this brief article, it is not possible to provide detailed

information about ongoing astrobiology research that is

changing our views of our world and the possibility of life

elsewhere. What I have done is to ask my colleagues to

submit references of recent articles that they believe

have made major contributions in their fields. I have

grouped these below under various astrobiology subject

headings along with brief descriptions of their content

and significance. This is not meant to be a complete

listing, but should provide an indication of the vitality

and breadth of the field. An excellent general reference

on astrobiology has been written by Des Marais and

Walter [3].

Extreme environments and extremophiles

Several groups have looked at extreme environments on

Earth, protracting their findings to possible conditions on

other planetary bodies. For example, Doran and colleagues

[4] report on Lake Vida, one of the largest lakes in

the McMurdo Dry Valleys of Antarctica, which was previously

believed to be frozen solid. However, it now turns

out to contain a briny liquid (seven times seawater salinity,temperature below 108C)

beneath a 19 m thick ice

cover that has effectively isolated the brine for about 2800

years. The ice cover contains microbial populations that

are metabolically active upon thawing. The physical

features and geological history of the lake suggest it

may be an analog of the last vestige of an ancient Martian

aquatic ecosystem.

Similarly, Kelley and coworkers [5] describe a new class

of marine hydrothermal system hosted on peridotites.

The field hosts at least 30 active and inactive 30–60 m

tall carbonate chimneys that vent fluids at 40–758C with

pH values of 9–10. The chimneys harbor dense and

diverse microbial communities. Because this system is

hosted in peridotites, it is very reducing and associated

with high pH fluids. It may be the best current analog

to hydrothermal systems that operated on early Earth

(Figure 1).

Other groups have investigated various environments,

including winter sea-ice [6] (Figure 2), active sulfide

chimneys [7,8], and the acidic, iron-rich red river, Rio

Tinto, in Southern Spain [9]. Together, these types of

studies have highlighted the harsh environments in which

life can exist and have helped scientists understand the

range of environments outside Earth that may harbor

microbial life.

Geological sciences

Sudbury in Ontario is the largest known and most important

bolide impact structure (astrobleme) on Earth, being

one of the first to be recognized and debated. Its many

geological features are exposed at the Earth’s surface, and

Box 2 Astrobiology book and journal list (since 2000).

Textbooks

Bennett J, Shostak S, Jakosky B: Life in the Universe. Boston:

Addison Wesley; 2003.

For introductory college courses for nonscience majors; stronger

on the physical sciences than biology

Goldsmith D, Owen T: The Search for Life in the Universe, 3rd Edn.

San Francisco: Benjamin Cummings; 2002.

For introductory college courses for nonscience majors; stronger

on the physical sciences than biology

Prather E, Offerdahl E, Slater T: Life in The Universe Activities

Manual. Boston: Addison-Wesley; 2003.

Student activities to accompany the textbook by Bennett et al.

Zubay G: Origins of Life on the Earth and in the Cosmos, 2nd Edn.

London: Harcourt; 2000.

Tutorial approach to the biochemistry of how life works and its origin

Popular books

Clark S: Life on Other Worlds and How to Find It. New York:

Springer-Praxis: 2000.

Darling D: Life Everywhere: the Maverick Science of Astrobiology.

New York: Basic Books; 2001.

Well-written; includes personalities of researchers

Darling D: The Extraterrestrial Encyclopedia: an Alphabetical

Reference to All Life in the Universe. Three Rivers; 2001.

deDuve C: Life Evolving: Molecules, Mind, and Meaning. Oxford UK:

Oxford University Press; 2002.

Nobelist argues for the inevitability of the emergence of life

Dick S: Life on Other Worlds: the 20th Century Extraterrestrial Life

Debate. Cambridge UK: Cambridge University Press; 2001.

Shorter, popular version of ‘The Biological Universe’ listed below

Fry I: The Emergence of Life on Earth: a Historical and Scientific

Overview. New Jersey: Rutgers University Press; 2000.

Excellent overview of past and current ideas on the origin of life

Grady M: Astrobiology. Washington: Smithsonian Institution Press; 2001.

Nice slim volume

Koerner D, Levay S: Here be Dragons: the Scientific Quest for

Extraterrestrial Life. Oxford UK: Oxford University Press; 2000.

Ward P: Rivers in Time: the Search for Clues to Earth’s Mass

Extinctions. Columbia: Columbia University Press; 2000.

Ward P, Brownlee D: Rare Earth: Why Complex Life is Uncommon in

the Universe. Copernicus, 2000.

Pioneering synthesis; astronomer and paleontologist argue that planets

with conditions for life more complex than single cells are

rare in the Universe

Ward P, Brownlee D: The Life and Death of Planet Earth: How the

New Science of Astrobiology Charts the Ultimate Fate of Our

World. New York: Henry Holt; 2003.

Wills C, Bada J: The Spark of Life: Darwin and the Primeval Soup.

Cambridge MA: Perseus; 2000.

Scholarly publications

Dick S: The Biological Universe: the Twentieth-Century

Extraterrestrial Life Debate and the Limits of Science.

Cambridge UK: Cambridge University Press; 2000.

The definitive historical study of the development over the 20th

century of ideas (both scientific and more popular, e.g. UFOs) on

extraterrestrial life, origin of life, exobiology and astrobiology

Horneck G, Baumstark-Khan C (Eds): Astrobiology: The Quest for the

Conditions of Life. New York: Springer; 2002.

Most chapters (by separate authors) are an outgrowth of a

workshop on astrobiology held in Germany; uneven coverage

Lemarchand G, Meech K (Eds): Bioastronomy ‘99: A New Era in

Bioastronomy. Proceedings of the Astronomical Society of the

Pacific Conference; Hawaii, USA, 2–6 August 1999. Vol. 213.

ASP, 2000.

Proceedings of a wide-ranging conference; strongest on the astronomy

Journals

Astrobiology. New York: Mary Ann Liebert, Inc.; (2001–).

International Journal of Astrobiology. Cambridge UK: Cambridge

University Press; (2002–).

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it is one of the world’s largest sources of nickel ore. The

Fe-Ni-Cu-S ore was not derived from the bolide, but

formed by processes induced by the impact. Naldrett [10]

has reviewed our current understanding of this site in an

article that illustrates the contribution of the geological

sciences to astrobiology.

Planetary and atmospheric science

Astronomers are beginning to discover planets beyond

Earth’s solar system and new models are being proposed

for their formation [11]. Data from the Hubble Space

Telescope provided the first direct detection of the atmospheric

composition of a planet orbiting a star outside our

solar system [12]. Sodium was found in the atmosphere

of a planet orbiting a yellow, Sun-like star called HD

209458, located 150 light-years away in the constellation

Pegasus. Although this particular planet is a gas giant like

Jupiter and unlikely to harbor life, the study demonstrated

that it is feasible to measure the chemical makeup

of extrasolar planetary atmospheres and to potentially

search for the chemical markers of life (such as O2)

beyond our solar system [13].

Recent evidence strongly supports the view that Mars has

water that has flowed in the recent past, supporting the

notionthat subsurface brinesmayexist [14].Bolideimpacts

in the past may have thawed frozen subsurface water

leading to temporary episodes of rain and flash floods [15].

Earth may have actually frozen over completely in its

past, a phenomenon referred to as ‘Snowball Earth’.

Hoffman and Schrag [16] have recently reviewed this

field and Warren et al. [17] discuss where surface life may

have survived during one of these remarkable events.

Until recently, atmospheric scientists explained how early

Earth could remain unfrozen even when the sun was 30%

less luminous because they believed the atmosphere had

high levels of the greenhouse gas, carbon dioxide. This

view has now changed as Pavlov et al. [18] showed how

biogenic methane in an early anoxic atmosphere could

have served as the key greenhouse gas. Catling et al. [19]

showed that the high methane concentration in the early

atmosphere could also explain the oxidation of the atmosphere:

ultraviolet light’s decomposition of methane to

hydrogen and its escape to space would have left Earth

more oxidized before biogenic oxygen production.

Early evolution

As surprising as it may seem microbiologists are still

discovering on Earth entirely new kingdoms ofmicrobial

life including representatives from each of the three

Figure 1

Several groups have looked at extreme environments on Earth, protracting their findings to possible conditions on other planetary bodies. Kelley and

coworkers [5] described a new class of marine hydrothermal system from the mid-Atlantic Ridge that is hosted on peridotites, which may be the

best current analog to hydrothermal systems that operated on early Earth. The figure shows a hydrothermal vent off the coast of Washington State.

The structures at this site vent at temperatures up to 3008C. Detailed analyses of one of the sulfide structures shows that they host dense and

diverse microbial communities. (The photograph is reproduced with kind permission from D Kelley.)

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domains, the Bacteria, Archaea and Eucarya. One example

is described in the recent paper of Huber et al. [20]

who reported an unexpected group of the Archaea,

known species of which parasitize other members of

the Archaea.

Much confusion still exists about the evolution of the first

organisms. Woese [21] considers the importance of horizontal

gene transfer on the evolution of early cellular life.

He proposed the ‘Darwinian Threshold’ as a seminal

period that separates early evolution in which horizontal

gene transfer dominated evolutionary processes from the

subsequent period in which evolution followed the vertical

inheritance of life as we now know it.

Although evidence indicates that many of the traits of the

Eucarya can be traced to the Bacteria and Archaea, until

recently tubulin genes have only been found in the

Eucarya, all species of which have them. However, this

too is no longer true; a bacterium that contains a- and

b-tubulin homologs has now been discovered [22].

Paleontology

Shen et al. [23] demonstrate the existence of microbial

sulfate reduction as early as 3.45 billion years ago, providing

the first evidence of a specific metabolism in

Earth’s evolutionary record. As this is typically a heterotrophic

metabolism in which organic matter is oxidized

anaerobically with sulfate, it implies that microbial ecosystems

were already quite diverse with complex trophic

webs and biogeochemical cycles. As sulfate reduction

requires sophisticated biochemical control, it further

implies that soon after the end of heavy meteorite bombardment

of the Earth, life was already quite advanced in

its cellular functions.

Considerable doubt has been cast on the claim that there

is carbon-isotopic evidence for life on Earth older than

3.85 Ga [24,25]. If correct, this claim would imply that

autotrophic organisms inhabited the Earth at the time of

the heavy meteorite bombardment and therefore that life

could have been widespread in the early solar system. Van

Zuilen et al. [24] argue that the observed carbon-isotope

fractionation is not biotic, but is instead the result of

metamorphic carbonate reduction to graphite. Fedo and

Whitehouse [25] argue that the host rock for this graphite

is an altered igneous rock and not a sedimentary banded

iron formation, so it should not be expected to host

biological remains.

Planetary protection and the search for

extraterrestrial intelligence

Astrobiologists are concerned about the biological contamination

of planetary bodies by life from elsewhere.

Figure 2

Sea-ice on Earth has become a model system in which to study planetary bodies such as Jupiter’s moon Europa, which has a frozen ocean that is

shown in close-up view. The texture of the ocean supports the view that there are large blocks of ice floating on a liquid ocean that may support

microbial life. (Figure reproduced with courtesy of the Jet Propulsion Laboratory at NASA/Caltech.)

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Rummel [26] has written an accessible review of the

history and state of planetary protection policy and implementation.

More specific issues, such as the handling and

quarantine of samples returned from elsewhere (e.g.Mars),

have been considered in some detail [27].

In part 1 of a comprehensive treatment of biological

transfer, Mileikowsky et al. [28] discuss the potential

for the natural transfer of microbes between solar system

bodies. This is based on knowledge that large impact

events (from comets or asteroids) occurring on one body

can propel significant quantities of material off a planetary

surface and into solar orbits that may intersect the orbits

of other bodies.

The search for extraterrestrial intelligence (SETI) continues

as one of the earliest endeavors that has attempted

to discover advanced life on other planetary bodies [29].

NASA’s astrobiology website contains links to the NAI

projects as well as an Astrobiology Roadmap that

describes research goals. Perhaps what is most remarkable

is that, during the past decade, this field has grown from a

small core of dedicated scientists to a large and impressive

group with many young scientists. With the emergence of

new technologies, such as genome sequencing and extrasolar

system planetary discovery techniques, our understanding

in all areas from molecular evolution to planetary

habitability is rapidly transforming our comprehension

of astrobiology.

Astrobiology’s promise for multidisciplinary

science education and research

Most educators agree there is a need to rethink science

and engineering education. Many of the traditional disciplines

seem to lack context in our modern world, at least

to many young scholars. By incorporating astrobiology

into a curriculum, the treatment of subject matter

changes. For example, consider the biology instructor

who is interested in teaching about the diversity of life.

A typical approach would be to discuss the different

species from each of the numerous animal groups and

how some are being threatened with extinction due to

habitat loss. In an astrobiology course the diversity issue

could be addressed in the context of mass extinctions,

such as, ‘What happened to the dinosaurs?’ The answer to

this question entails a discussion of biology, paleontology,

astronomy, physics (for dating fossils), evolution and

could be followed up by a discussion of the human-driven

mass extinction that is occurring now. Therefore, astrobiology

can provide a compelling way of integrating the

sciences in the classroom.

Also, from a pragmatic standpoint, the subject matter in

astrobiology is very flexible. It can be taught within the

structure of an entire science curriculum at one extreme,

or as a single course. Furthermore, astrobiology can be

taught to all educational levels and it serves as an engaging

outreach program to the public.

Because of the interest in astrobiology courses, several

books have recently been published, some of which could

serve as textbooks for courses at the undergraduate and

graduate levels (Box 2).

Policy recommendations for astrobiology

science education and research

PhD traineeship programs

Evidence from our University of Washington National

Science Foundation (NSF) Integrative Graduate Education

and Research Traineeship (IGERT) astrobiology

program (http://depts.washington、edu/astrobio/) indicates

that astrobiology can serve as an excellent subject area for

interdisciplinary PhD education in science and engineering.

Because astrobiology is such a broad and exciting

field of study in science, it should be promoted as a

curriculum in science education and research at the

doctoral level.

We recommend that NASA, NSF and other appropriate

federal agencies should provide support for the implementation

of PhD traineeship programs in science and

engineering education in astrobiology. This will develop

a unique group of scientists and engineers who will be

able to effectively communicate and collaborate with one

another. Furthermore, they will be able to subsequently

train university students in astrobiology and interdisciplinary

research.

Astrobiology students who receive PhD degrees will be

ideal candidates for the instruction of courses for doctoral

students interested in astrobiology. At this time there are

very few students. Even when more students graduate,

however, it should be recognized that they will not have

the in-depth experience to supervise students in PhD

courses and research in areas outside their own disciplinary

expertise, so a co-mentoring approach appears more

appropriate. Astrobiology students trained in our program

complete all of the necessary requirements in their major

department and, in addition, complete the requirements

for the astrobiology program. Therefore, they can compete

effectively for post-graduate opportunities with

others in their own area, but have the added experience

of working in a multidisciplinary training environment,

which, we believe, makes them better prepared for their

future careers.

Astrobiology PhD programs are likely to remain interdepartmental

for the foreseeable future. Although they

may eventually be accepted as departmental programs,

this seems premature now as it may actually detract from

the true vision of a cross-disciplinary field. Nonetheless, if

life is discovered elsewhere in our solar system or in

another planetary system, it could certainly lead to a need

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to train additional astrobiologists through university

departmental programs. In this sense, an astrobiology

training program could serve as a forerunner for the cadre

of scientists and engineers eventually needed.

The current NSF IGERT program is an excellent model

to use for development of a joint NASA-NSF or other

agency program, because of the importance it places on

integrative student training and support for development

of novel educational ideas.

Undergraduate university level

Astrobiology is currently amenable for the instruction of

undergraduate students in single courses. Textbooks are

available that may be used for that purpose if institutions

have faculty members who can teach in the various

subject areas.

Because astrobiology covers such a vast area, most instructors

will find it difficult to teach an entire course; however,

it could be team-taught by faculty from biology and the

physical sciences. Ultimately, as PhD scientists and engineers

are trained in astrobiology, they would become

ideal candidates to teach an entire course at the undergraduate

level.

Our recommendation for teaching astrobiology at the

undergraduate level is to provide support for training of

existing faculty at institutions that wish to develop astrobiology

courses or a curriculum. This could be handled by

supporting faculty study leaves to a university in which a

graduate level program in astrobiology is in place, as well

as at the various non-academic NAI institutions.

Primary and secondary education

Astrobiology is an exciting field that is ideal for teaching

science to students in secondary education. Some materials

are currently available for this such as Astro-Venture

for grades 5–8, at the NAI site mentioned previously, and

the SETI Institute high school curriculum (www.seti、org/Welcome.html).

However, there is a need to train teachers

and develop additional instructional materials. This

could be initiated with a trial period at primary and

secondary schools that wish to pursue this subject matter

in their science curriculum. Once this trial period is over,

say after five years, the concept could be evaluated and, if

appropriate, implemented.

To teach astrobiology at this level we recommend that

support is provided for workshops and course planning

sessions for scientists from universities with astrobiology

programs and science teachers of primary and secondary

school students. The goal of these workshops is to

develop trial curricula for teaching astrobiology at the

primary and secondary levels. It would also be necessary

to support the development of astrobiology courses and

appropriate educational materials (textbooks, videos,websites, etc)

that could be used for teaching primary,

secondary and undergraduate students interested in

science and engineering.

Conclusions

Recent advances in scientific knowledge from such disparate

areas as microbiology, astronomy, geochemistry,

paleontology, genomics, planetary science and molecular

evolution have culminated in the formation of the new

field of astrobiology. Astrobiology, which transcends virtually

all of the sciences, aims to answer the great questions

about the origin of life and its distribution and

evolution in the Universe. Astrobiology has quickly

ascended to international prominence as a novel multidisciplinary

and integrated scientific research area.

Because of its innately interesting subject material, astrobiology

is ideally suited for teaching science from kindergarten

to the graduate level. Now is the time to

implement astrobiology into educational programs in

the form of new courses and new curricula. In order to

accomplish this goal, governmental resources will be

needed to train teachers and develop appropriate instructional

guidelines and materials.

Acknowledgements

I want to thank my colleagues at the University of Washington who have

made suggestions and provided some of the references mentioned,

especially Roger Buick, David Catling, Eric Cheney, Jody Deming,

Deborah Kelley, Marsha Landolt, Thomas Quinn, Steve Warren and Llyd

Wells. In addition, I wish to thank David Morrison who provided the book

listing and Woodruff Sullivan III who provided book annotations. Also

thanks to Rosalind Grymes and John Rummel for their excellent

suggestions, most of which I have adopted. I am also grateful to the NSF

IGERT and NASA NAI programs for providing support for my laboratory’s

research in astrobiology.

References and recommended reading

Papers of particular interest, published within the annual period of

review, have been highlighted as:

of special interest

of outstanding interest

1.

Armstrong J, Wells L, Gonzalez G: Rummaging through Earth’s

attic for remains of ancient life. Icarus 2002, 160:183-196.

This paper suggests that the moon may contain fossils of early Earth

organisms in rocks that were ejected to the moon by impacts.

2.

Wells L, Armstrong J, Gonzalez G: Reseeding Earth by impacts of

returning ejecta during the late heavy bombardment. Icarus: in

press.

Since the moon probably received ejecta from early Earth, returning

ejecta from the moon could have re-inoculated the Earth, which might

have been sterilized by large impacts.

3.

Des Marais D, Walter M: Astrobiology: exploring the origins,

evolution, and distribution of life in the Universe. Annu Rev Ecol

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